Battle of France

Battle of France
Part of the Western Front of the Second World War
Clockwise from top left: German Panzer IV tanks passing through a town in France; German soldiers marching past the Arc de Triomphe after the surrender of Paris, 14 June 1940; Column of French Renault R35 tanks at Sedan, Ardennes; British and French prisoners at Veules-les-Roses; French soldiers on review within the Maginot Line fortifications.
Date 10 May – 22 June 1940 (1-month, and 12 days) Location France, Low Countries Result Decisive Axis victory Replacement of French Third Republic by Vichy France
Belligerents
Allies: France  United Kingdom  Belgium  Netherlands  Canada Poland Czechoslovakia  Luxembourg	Axis:  Germany   Italy (from 10 June)
Commanders and leaders
Maurice Gamelin (until 17 May) Alphonse Georges (until 17 May) Maxime Weygand (from 17 May) Lord Gort Leopold III Henri Winkelman	Gerd von Rundstedt Heinz Guderian Fedor von Bock Wilhelm von Leeb Erich von Manstein Erwin Rommel Hermann Hoth H.R.H. Umberto di Savoia
Units involved
Allied armies 1st Army Group Seventh Army BEF Belgian Army Ninth Army Second Army 2nd Army Group Third Army Fourth Army Fifth Army 3rd Army Group Eighth Army Dutch Army From 10 June in Alpes: Sixth Army	Axis armies Army Group B Eighteenth Army Sixth Army Army Group A Third Army Twelfth Army Sixteenth Army Army Group C First Army Seventh Army From 10 June in Alpes: Army Group West First Army Fourth Army
Strength
Allies: 144 divisions 13,974 guns 3,383 tanks 2,935 aircraft 3,300,000 troops Alps on 20 June ~150,000 French	Germany: 141 divisions 7,378 guns 2,445 tanks 5,638 aircraft 3,350,000 troops Alps on 20 June 300,000 Italians
Casualties and losses
360,000 dead or wounded, 1,900,000 captured 2,233 aircraft Total: 2,260,000 casualties	Germany: 157,621 casualties 1,236-1,345 aircraft destroyed 323-488 aircraft damaged 795 tanks destroyed Italy: 6,029 Total: 163,650 casualties

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Western Front Prelude 1939 Phoney War Saar The Heligoland Bight 1940 Luxembourg The Netherlands The Hague Rotterdam Zeeland Rotterdam Blitz Belgium Fort Eben-Emael Hannut Gembloux La Lys France Sedan Bulson Montcornet Arras Lille Calais Abbeville Paula Dunkirk Dunkirk evacuation Italian Invasion of France Saumur Britain Adlertag The Hardest Day Battle of Britain Day Sea Lion 1942–1943 Cerberus and Donnerkeil St Nazaire Raid Dieppe Raid 1944–1945 Overlord Dragoon Siegfried Line Market Garden Arnhem Hürtgen Forest Aachen Queen Scheldt Bulge Nordwind Bodenplatte Colmar Pocket Atlantic Pockets Invasion of Germany Strategic Campaigns The Blitz Defence of the Reich Raids on the Atlantic Wall Battle of Atlantic

In the Second World War, the Battle of France, also known as the Fall of France, was the successful German invasion of France and the Low Countries, beginning on 10 May 1940, defeating primarily French forces. The battle consisted of two main operations. In the first, Fall Gelb (Case Yellow), German armoured units pushed through the Ardennes to cut off and surround the Allied units that had advanced into Belgium. When British and adjacent French forces were pushed back to the sea by the highly mobile and well organised German operation, the British government decided to evacuate the British Expeditionary Force (BEF) as well as several French divisions at Dunkirk in Operation Dynamo.

With France left to fend for itself after the British evacuation, Germany launched a second operation, Fall Rot (Case Red), which was commenced on 5 June. Initially the depleted French forces put up stiff resistance, but German air superiority gradually overwhelmed French artillery positions. German forces outflanked the Maginot Line and pushed deeper into France as French forces began to collapse. German forces arrived in an undefended Paris on 14 June and their commanders met with French officials who sought an alliance with Germany. Chief among these was Marshal Philippe Pétain who, contrary to the wishes of many Frenchmen, announced he would seek an armistice.

On 22 June, an armistice was signed between France and Germany, which resulted in a division of France whereby Germany would occupy the north and west, Italy would control a small Italian occupation zone in the southeast, and an unoccupied zone, the zone libre, would be governed by the newly formed Vichy government led by Marshal Pétain. France remained under Axis occupation until the liberation of the country after the Allied landings in 1944.

Prelude

Following the invasion of Poland in September 1939 (which started the Second World War in Europe), a period of inaction called the Phony War ("Sitzkrieg" or "Drôle de guerre") set in between the major powers. Adolf Hitler had hoped that France and Britain would acquiesce in his conquest and quickly make peace. On 6 October, he may have made some type of peace offer to both Western Powers. Even before they had time to respond, on 9 October, he also formulated a new military policy in case their reply was negative: Führer-Anweisung N°6, or " Führer-Directive Number 6".

German strategy

Hitler had always fostered dreams about major military campaigns to defeat the Western European nations as a preliminary step to the conquest of territory in Eastern Europe, thus avoiding a two-front war. However, these intentions were absent from Führer-Directive N°6. This plan was firmly based on the seemingly more realistic assumption that Germany's military strength would still have to be built up for several more years and that for the moment only limited objectives could be envisaged. They were aimed at improving Germany's ability to survive a long, protracted war in the West. Hitler ordered a conquest of the Low Countries to be executed at the shortest possible notice. This would stop France from occupying them first, and prevent Allied air power from threatening the vital German Ruhr Area. It would also provide the basis for a long-term air and sea campaign against Britain. There was no mention in the Führer-Directive of any immediate consecutive attack to conquer the whole of France, although as much as possible of the border areas in northern France should be occupied.

While writing the directive, Hitler had also assumed that such an attack could be initiated within a period of at most a few weeks, but the very day he issued it he was disabused of this illusion. It transpired that he had been misinformed about the true state of Germany's forces. The motorised units had to recover, repairing the damage to their vehicles incurred in the Polish campaign, and ammunition stocks were largely depleted.

German armed forces structure

The overall command for all the German armed forces was the Oberkommando der Wehrmacht (usually contracted to OKW). This was sometimes used by Hitler as an alternative army planning staff, but the direction of the offensive on the western front was the responsibility of the Oberkommando des Heeres or OKH, the Army supreme command. The commander in chief of the Army was General Walther von Brauchitsch, but the main responsibility for planning belonged to the Chief of Staff, Franz Halder.

Under OKW, the other service commands were the Oberkommando der Luftwaffe or OKL, led by Hitler's close political colleague Hermann Göring, and the Oberkommando der Marine or OKM, led by Admiral Erich Raeder.

Similarity to Schlieffen Plan

On 10 October 1939, the British refused Hitler's offer of peace; on 12 October, the French did the same. Franz Halder, the chief of staff of the Army (Generalstabschef des Heeres), presented the first plan for Fall Gelb ("Case Yellow") on 19 October. This was the pre-war codename of plans for a campaign in the Low Countries: the Aufmarschanweisung N°1, Fall Gelb ("Deployment Instruction No. 1, Case Yellow"). Halder's plan has often been compared to the Schlieffen Plan, which the Germans attempted to execute in 1914 in the opening phase of the First World War. It was similar in that both plans entailed an advance through the middle of Belgium, but while the intention of the Schlieffen Plan was to gain a decisive victory by executing a rapid encirclement of the French Army, Aufmarschanweisung N°1 envisioned a frontal attack, sacrificing a projected half million German soldiers to attain the limited goal of throwing the Allies back to the River Somme. Germany's strength for 1940 would then be spent; only in 1942 could the main attack against France begin.

Hitler was disappointed with Halder's plan and initially reacted by deciding that the German army should attack early, ready or not, in the hope that Allied unpreparedness might bring about an easy victory. This led to a series of postponements, as commanders repeatedly persuaded Hitler to delay the attack for a few days or weeks to remedy some critical defect in the preparations, or to wait for better weather. Hitler also tried to alter the plan which he found unsatisfactory, without clearly understanding how it could be improved. This mainly resulted in a dispersion of effort; although the main axis would remain in central Belgium, secondary attacks would be undertaken on the flanks. Hitler made such a suggestion on 11 November. On 29 October, Halder let a second operational plan, Aufmarschanweisung N°2, Fall Gelb, reflect these changes by featuring a secondary attack on the Netherlands.

Hitler was not alone in disliking Halder's plan. General Gerd von Rundstedt, the commander of Army Group A, also disagreed with it. Von Rundstedt recognised that it did not adhere to the classic principles of the Bewegungskrieg (" manoeuvre warfare") which had guided German strategy since the 19th century. A breakthrough would have to be accomplished that would result in the encirclement and destruction of the main body of Allied forces. The most practical place to achieve this would be in the region of Sedan, which lay in the sector of von Rundstedt's Army Group. On 21 October, von Rundstedt agreed with his chief of staff, Generalleutnant Erich von Manstein, that an alternative operational plan had to be arranged that would reflect these basic ideas, making Army Group A as strong as possible at the expense of Army Group B to the north.

Manstein Plan

Whilst von Manstein was formulating new plans in Koblenz, Generalleutnant Heinz Guderian, commander of the XIX Army Corps, Germany's elite armoured formation, happened to be lodged in a nearby hotel. At this moment, von Manstein's plan consisted of a move directly north from Sedan against the rear of the main Allied forces in Belgium. When Guderian was invited to contribute to the plan during informal discussions, he proposed a radical and novel idea. Not only his army corps, but most of the Panzerwaffe should be concentrated at Sedan. This concentration of armour should subsequently not move to the north but to the west, to execute a swift, deep, independent strategic penetration towards the English Channel without waiting for the main body of infantry divisions. This might lead to a strategic collapse of the enemy, avoiding the relatively high number of casualties normally caused by a Kesselschlacht ("annihilation battle"). Such a risky independent use of armour had been widely discussed in Germany before the war but had not been accepted as received doctrine. The German General Staff, however, doubted such an operation could work. Von Manstein's operational idea won immediate support from Guderian. Guderian understood the terrain, having experienced the conditions with the German Army in 1914 and 1918.

Von Manstein wrote his first memorandum outlining the alternative plan on 31 October. In it he carefully avoided mentioning Guderian's name and played down the strategic part of the armoured units, in order to not generate unnecessary resistance. Six more memoranda followed between 31 October 1939 and 12 January 1940, each becoming more radical in outline. All were rejected by the OKH, the German Army's headquarters, and nothing of their content reached Hitler.

Mechelen Incident

On 10 January, a German Messerschmitt Bf 108 made a forced landing at Maasmechelen, north of Maastricht, in Belgium (the so-called " Mechelen Incident"). Among the occupants of the aircraft was Luftwaffe Major Hellmuth Reinberger, who was carrying a copy of the latest version of Aufmarschanweisung N°2. Reinberger was unable to destroy the documents, which quickly fell into the hands of the Belgian intelligence services. It has often been suggested that this incident was the cause of a drastic change in German plans, but this is incorrect; in fact, a reformulation of them on 30 January, Aufmarschanweisung N°3, Fall Gelb, conformed to the earlier versions.

Adoption of Manstein Plan

On 27 January, von Manstein was relieved of his appointment as Chief of Staff of Army Group A and appointed commander of an army corps in Prussia, to begin his command in Stettin on 9 February, a move instigated by Halder to reduce von Manstein's influence. Von Manstein's indignant staff brought his case to Hitler's attention. Hitler had, without any knowledge of von Manstein's plan, suggested an attack focused at Sedan but had been persuaded to forget the idea as it was too risky. On 2 February, von Manstein's plan was brought to his attention. On 17 February, Hitler summoned von Manstein, Generals Rudolf Schmundt (the German Army's Chief of Personnel) and Alfred Jodl, the Chief of Operations at the OKW (the German armed forces' supreme command), to attend a conference. Hitler sat and listened, abandoning his habits of interrupting and launching into monologues. In the end, he agreed to all of von Manstein's suggestions. The next day, he ordered the plans to be changed in accordance with von Manstein's ideas. They appealed to Hitler mainly because they offered some real hope of victory. Hitler recognised the breakthrough at Sedan only in tactical terms, whereas von Manstein saw it as a means to an end. He envisaged an operation to the English Channel and the encirclement of the Allied armies in Belgium, which, if carried out correctly, could have a favourable strategic outcome.

Halder had no intention of deviating from established doctrine by allowing an independent strategic penetration by the seven armoured divisions of Army Group A. Much to the outrage of Guderian, this element was at first completely removed from the new plan, Aufmarschanweisung N°4, Fall Gelb, issued on 24 February. However, Halder went through an "astonishing change of opinion". Halder was criticised in the same way he had attacked von Manstein when he first suggested it. The bulk of the German officer corps was appalled by the plan, and they called him the "gravedigger of the Panzer force".

Even when adapted to more conventional methods, the new plan provoked a storm of protest from the majority of German generals. They thought it utterly irresponsible to create a concentration of forces in a position where they could not possibly be sufficiently supplied, while such inadequate supply routes as there were could easily be cut off by the French. If the Allies did not react as expected, the German offensive could end in catastrophe. Their objections were ignored. Halder argued that, as Germany's strategic position seemed hopeless anyway, even the slightest chance of a decisive victory outweighed the certainty of ultimate defeat implied by inaction.

Blitzkrieg

The strategy, operational methods and tactics of the German Army and Luftwaffe has often been labelled "Blitzkrieg" (Lightning War). The concept is deeply controversial and is connected to the problem of the precise nature and origin of "Blitzkrieg" operations, of which the 1940 campaign is often described as a classic example. An essential element of "Blitzkrieg" was considered to be a strategic, or series of operational developments, executed by mechanised forces which led to the total collapse of the defenders' armed forces. "Blitzkrieg" has also been looked on as a revolutionary form of warfare. In recent years, its novelty and even its very existence have been disputed.

Rapid and decisive victories had been pursued by armies well before the Second World War. In the German wars of unification and First World War campaigns, the German General Staff had attempted Bewegungskrieg (Movement War), similar to the modern perception of "Blitzkrieg", with varying degrees of success. During the First World War, these methods often succeeded in achieving tactical breakthroughs, but the operational exploitation took time as armies lacked motorisation, could not move quickly, and sometimes failed to achieve a decisive victory altogether. The development of tanks, aircraft, and more importantly, motorised infantry and artillery, enabled the Germans to implement these old methods again with new technology in 1940. The combustion engine solved the problem of operational level exploitation.

When dealing with "Blitzkrieg" as a concept, things become complicated. It is seen as an anomaly and there is no explicit reference to such strategy, operations or tactics in the German battle plans. There is no evidence in German military art, strategy or industrial preparation that points to the existence of a thought out "Blitzkrieg" tendency. Evidence suggests that the German Reich was preparing for a long sustained war of attrition, not a quick war of manoeuvre. Hitler's miscalculations in 1939 forced him into war before he was ready, and under these circumstances the German General Staff reverted to attempting to win a quick war, before the economic and material superiority of the Allies could make a difference, although this was not their original intention. It was only after the defeat of France in 1940, that the German military pursued a "Blitzkrieg"-kind of warfare to achieve its ambitions in Europe. German historian Karl-Heinz Frieser explained:

"The campaign in the west was not a planned campaign of conquest. Instead, it was an operational act of despair to get out of a desperate strategic situation. What is called "Blitzkrieg thinking" did not develop until after [author's emphasis] the campaign in the west. It was not the cause but rather the consequence of victory. Something that in May 1940, had come off successfully to everyone's surprise, was now to serve the implementation of Hitler's visions of conquest in the form of the secret success.

Allied strategy

Early actions

In September 1939, Belgium and the Netherlands were still neutral. They had made arrangements in secret with the Entente (as the Allies were still widely called) for future cooperation should the Germans invade their territory. The Supreme Commander of the French Army— Maurice Gamelin—suggested during that month that the Allies should take advantage of the fact that Germany was tied up in Poland by using the Low Countries as a spring board to attack Germany. This suggestion was not taken up by the French government.

Just after the 1 September 1939 invasion of Poland, French soldiers advanced along the Maginot Line 5 km (3.1 mi) into the Saar which was called the Saar Offensive. France had employed 98 divisions (all but 28 of them reserve or fortress formations) and 2,500 tanks against German forces consisting of 43 divisions (32 of them reserves) and no tanks. They advanced until they met the then thin and undermanned Siegfried Line. The French army would easily have been able to penetrate the mere screen of German forces present had they continued with the offensive, but they preferred to force the Germans into the offensive role and withdrew to their own lines in October.

Dyle Plan

Strategic reasons dictated the Allied decision to advance and fight on Belgian territory when the German attack came in the west. The British government insisted that the Flemish coast remain under Allied control so as not to threaten British naval supremacy. The French determined that the German offensive had to be contained as far east as possible, to keep the battles off French territory. Finally, and for him personally, the most cogent argument for advancing and fighting on Belgian territory was that Gamelin did not consider the French army capable of winning a mobile battle against the German army in the wide operational theatre France would present. Belgium presented a far narrower front to contain German formations. He also argued that an advance to the Dyle river and preparing an entrenched front there saved most of Belgium's industrial regions from falling into German hands.

Gamelin did not have the personality to simply impose his will. The first step he took was to propose the " Escaut" variant as an option for Plan D, the code for the "Dyle plan". This would include an advance by the French onto Dutch territory. The powerful French 1st and 9th Armies would hold the line in Belgium, from Wavre to Givet. The French 7th Army would hold the line on the Scheldt and link up with Dutch forces. The Belgian Army would hold the Ghent-Antwerp line. They would be reinforced by the British Army, which would hold the section of the line east of Brussels, from Wavre to Louvain.

Gamelin made the reasonable assumption that the Germans would try to attempt a breakthrough by concentrating their mechanised forces. They could hardly hope to break the Maginot Line on his right flank or to overcome the Allied concentration of forces on the left flank. That only left the centre, but most of the centre was covered by the river Meuse. Tanks were limited in defeating fortified river positions. However, at Namur the river made a sharp turn to the east, creating a gap between itself and the river Dyle. This ' Gembloux Gap', ideal for mechanised warfare, was a very dangerous weak spot. Gamelin decided to concentrate half of his armoured reserves there, sure the main German thrust would be on the Belgian-Dutch plain. Gamelin reasoned that the Germans might try to overcome the Meuse position by using infantry, but he was confident in the Belgians' ability to hold the line and believed that while it was possible for the Germans to cross the Meuse, it would take a long time to achieve. Gamelin made no study in the event of a German breakthrough in the south, and as a consequence, did not make preparations to extricate Allied forces from Belgium.

Gamelin continued with his plans despite repeated criticism from his subordinates. Gaston Billotte (the commander-in-chief of the First Army Group) and Alphonse Joseph Georges (commander-in-chief of the North-Eastern front which included the First and Second Army Groups) were particularly critical. Georges pointed out the decisive problem. He suggested that Gamelin was too sure the German plan involved the battles, or main effort, being fought in the Netherlands and Belgium. He argued that it seemed as if Gamelin was allowing himself to be drawn into the Low Countries. He even suggested that an attack in Belgium might be a diversion. In this case, if the main forces were sent into Belgium and "the main enemy attack came in our centre, on our front between the Meuse and the Moselle, we could be deprived of the necessary means to repel it".

The development of Allied strategy was exclusively in the hands of the French. The British, recognising they were the smaller partner in the alliance, agreed to French proposals.

Allied intelligence

In the winter of 1939–1940, the Belgian consul-general in Cologne had anticipated the angle of advance that Von Manstein was planning. Through intelligence reports, they deduced that German forces were concentrating along the Belgian and Luxembourg frontiers. The Belgians were convinced that the Germans would thrust through the Ardennes and to the English Channel with the aim of cutting off the Allied field armies in Belgium and north-eastern France. They also anticipated that the Germans would try to land airborne and glider forces behind the Allied lines to break open Belgian fortifications. Such warnings were not heeded by the French or British.

In March 1940, Swiss intelligence detected six or seven Panzer Divisions on the German-Luxembourg-Belgian border. More motorised divisions had also been detected in the area. French intelligence were informed that the Germans were constructing pontoon bridges partially—about halfway—over the Our River on the Luxembourg-German border through aerial reconnaissance. The French military attaché in the Swiss capital— Berne—warned that the centre of the German assault would come on the Meuse at Sedan, sometime between 8 and 10 May. The report was dated 30 April. These reports had little effect on Gamelin.

German forces and dispositions

Strength

Germany had mobilised 4,200,000 men of the Heer, 1,000,000 of the Luftwaffe, 180,000 of the Kriegsmarine, and 100,000 of the Waffen-SS. When consideration is made for those in Poland, Denmark and Norway, the Army had 3,000,000 men available for the offensive on 10 May 1940. These manpower reserves were formed into 157 divisions. Of these, 135 were earmarked for the offensive, including 42 reserve divisions.

The German forces in the West in May and June deployed some 2,439 tanks and 7,378 artillery guns, including matériel reserves committed. In 1939–40, 45% of the army was at least 40 years old, and 50% of all the soldiers had just a few weeks training. Contrary to what the blitzkrieg legend suggests, the German Army was not fully motorised. Just 10% of the Army was motorised in 1940 and could muster only 120,000 vehicles, compared to the 300,000 of the French Army. The British also had an "enviable" contingent of motorised forces. Most of the German logistical tail consisted of horse-drawn vehicles.

Only 50% of the German divisions available in 1940 were combat ready, often being more poorly equipped than their equivalents in the British and French Armies, or even as well as the German Army of 1914. In the spring of 1940, the German army was semi-modern. A small number of the best-equipped and "elite divisions were offset by many second and third rate divisions".

Army operational deployment

The German Army was divided into three army groups. Army Group A commanded by Gerd von Rundstedt, composed of 45½ divisions including seven armoured, was to execute the decisive movement, cutting a "Sichelschnitt"—not the official name of the operation but the translation in German of a phrase after the events coined by Winston Churchill as "Sickle Cut" (and even earlier "armoured scythe stroke")—through the Allied defences in the Ardennes. It consisted of three armies: the 4th, 12th and 16th. It had three Panzer corps; one, the XV, had been allocated to the 4th Army, but the other two, the XXXXI (Reinhardt) and the XIX (Guderian) were united with the XIV Army Corps of two motorised infantry divisions, on a special independent operational level in Panzergruppe Kleist (officially known as XXII Corps).

Army Group B under Fedor von Bock, composed of 29½ divisions including three armoured, was tasked with advancing through the Low Countries and luring the northern units of the Allied armies into a pocket. It consisted of the 6th and 18th Armies. Army Group C, composed of 18 divisions under Wilhelm Ritter von Leeb, was charged with preventing a flanking movement from the east, and with launching small holding attacks against the Maginot Line and the upper Rhine. It consisted of the 1st and 7th Armies.

Communications

The real trump card for the Germans was the radio. The Panzers all had radios that allowed voice communication with other units. This enabled German armour to respond rapidly to a constantly changing battlefield situation. It allowed for last minute changes in tactics and improvisations to be formed far more quickly than the enemy. Some commanders regarded the ability to communicate the primary method of combat. Radio drills were even considered more important than firing accurately. Communication allowed German armour to coordinate their formations, bringing them together for a mass firepower effect in the attack or defence. This offset the French advantage in numbers and equipment, which was deployed in "penny-packets". The French also lacked radios and orders were passed from mouth to mouth. The opposing systems would give the Germans a decisive edge in battle.

The radio network went beyond tank to tank commands. The system also permitted a degree of communication between air and ground forces. Attached to Panzer Division was the Fliegerleittruppen (tactical air control troops) which were given wheeled vehicles. There were too few Sd.Kfz. 251 command vehicles to make this a uniform facility throughout the army, but the theory allowed the army in some circumstances to call upon the Luftwaffe units, while either on the ground or airborne, to support an attack that army artillery could not deal with. It is said that Guderian's Corps' dash to the channel never had to wait more than 15–20 minutes after making such a call, for the Luftwaffe to appear over the target. A specific Junkers Ju 87 group ( VIII. Fliegerkorps), which was to support the dash to the channel should Army Group A break through in the Ardennes, kept one Ju 87 and one fighter group ready for immediate take-off. On average, they could arrive to support armoured units within 45–75 minutes of orders being issued.

Army tactics

The main tool of the German land forces was combined arms combat. In contrast to the Allies, they relied on highly mobile offensive units, with balanced numbers of well trained artillery, infantry, engineer and tank formations, all integrated into Panzer divisions. They relied on excellent communication systems which enabled them to break into a position and exploit it before the enemy could react. Panzer divisions could carry out reconnaissance missions, advance to contact, defend and attack vital positions or weak spots. This ground would then be held by infantry and artillery as pivot points for further attacks. Although their tanks were not designed for tank-versus-tank combat, they could take ground and draw the enemy armour on to the division's anti-tank lines. This conserved the tanks to achieve the next stage of the offensive. The units' logistics were self-contained, allowing for three or four days of combat. The Panzer divisions would be supported by motorised and infantry divisions.

The German Army lacked a formidable heavy combat tank such as the French possessed. In armament and armour, French tanks were the stronger designs and more numerous (although the German vehicles were faster and more mechanically reliable). But while the German Army was outnumbered in artillery and tanks, it possessed some critical advantages over its opponents. The newer German Panzers had a crew of five men; a Commander, gunner-aimer, loader, driver and mechanic. Having a trained individual for each task allowed each man to dedicate himself to his own mission and it made for a highly efficient combat team. The French had fewer members, with the commander double-tasked with loading the main gun, distracting him from his main duties in observation and tactical deployment. It made for a far less efficient system.

Even within infantry formations, the Germans enjoyed an advantage through the doctrine of Auftragstaktik (Mission command tactics), by which officers were expected to use their initiative to achieve their commanders' intentions, and were given control of the necessary supporting arms.

Luftwaffe

One of the German strengths was the Luftwaffe. It divided its forces into two groups. In total, 1,815 combat, 487 transport and 50 glider aircraft were deployed to support Army Group B, while a further 3,286 combat aircraft were deployed to support Army Groups A and C.

The task of German aviation was to provide close air support in the form of the dive-bomber and medium bomber. In 1940, the Luftwaffe was a broadly based force with no constricting central doctrine, other than its resources should be used generally to support national strategy. It was flexible and it was able to carry out both operational, tactical and strategic bombing effectively. Flexibility was the Luftwaffe's strength in 1940. While Allied air forces, in 1940, were tied to the support of the army, the Luftwaffe deployed its resources in a more general, operational way. It switched from air superiority missions, to medium-range interdiction, to strategic strikes, to close support duties depending on the need of the ground forces. In fact, far from it being a dedicated Panzer spearhead arm, less than 15% of the Luftwaffe was designed for close support of the army in 1939, as this aspect was not its primary mission.

Anti-aircraft defences

It is generally supposed that the Germans also had a major advantage in anti-aircraft guns, or Flak. In reality, the generally cited figure of 2,600 88 mm (3.46 in) heavy Flak guns and 6,700 37 mm (1.46 in) and 20 mm (0.79 in) light Flak seems to refer to the German armed forces total inventory, including the anti-aircraft defences of Germany's cities and ports and the equipment of training units. (A 9,300-gun Flak component with the field army would have involved more troops than the entire British Expeditionary Force) The actual provision of Flak for the invading forces was 85 heavy and 18 light batteries belonging to the Luftwaffe, 48 'companies' of light Flak integral to divisions of the army, and 20 'companies' of light Flak allocated as army troops that is, as a disposable reserve in the hands of HQs above corps level: altogether about 700 88 mm (3.46 in) and 180 37 mm (1.46 in) guns manned by Luftwaffe ground units and 816 20 mm (0.79 in) guns manned by the army.

Allied forces and dispositions

Strength

France had spent a higher percentage of its GNP from 1918 to 1935 on its military than other great powers, and the government had begun a large rearmament effort in 1936. Due to a low birthrate, however, which had declined during the First World War and the Great Depression, and was exacerbated by the numbers of men who had been killed in the war, France had a severe manpower shortage relative to its total population, which was barely half that of Germany. To compensate, France had mobilised about one-third of the male population between the ages of 20 and 45, bringing the strength of its armed forces to 5,000,000. Only 2,240,000 of these served in army units in the north. The British contributed a total strength of 897,000 men in 1939, rising to 1,650,000 by June 1940. In May, it numbered only 500,000 men, including reserves. Dutch and Belgian manpower reserves amounted to 400,000 and 650,000 respectively.

Armies

There were 117 French divisions in total, of which 104 divisions (including 11 in reserve) were for the defence of the north. The British Army contributed only 13 divisions, three of which had not been organised when the campaign began. Some 22 Belgian, 10 Dutch and two Polish divisions were also a part of the Allied order of battle. British artillery strength amounted to 1,280 guns. Belgium fielded 1,338 and the Dutch, 656. France had 10,700 pieces. This made a total of around 14,000 artillery pieces. 45% more than the Germans. The French army was also more motorised than its opponent, which still relied heavily on horses. Although the Belgians, British and Dutch had barely any armour, the French had a powerful force of 3,254 tanks. The force was both larger and of higher quality than Germany's, as shown by its victory in Hannut, the largest tank battle of the campaign.

The French Army was of mixed quality. It had in its order of battle some formidable units, particularly the light and heavy armoured divisions ( DCR and DLM), and several professional infantry divisions. However, many divisions were composed of reserve soldiers, above 30 years old, and were ill-equipped. A serious qualitative deficiency was a lack of anti-air artillery, mobile anti-tank artillery and radio communication systems, despite the efforts of Gamelin to produce mobile artillery units. He used telephones and couriers to communicate with the field during the Battle of France; only 0.15% of military spending between 1923 and 1939 had been on radios and other communications equipment.

French tactical deployment and the use of mobile units operationally was also inferior to that of the Germans. Tactically, armour was spread thinly along the French line; French infantry divisions were supported by tank battalions of about 100 tanks, which prevented them from being a strong, independent operational force. Making matters worse, only a handful of French tanks in each unit had radios installed, and the radios themselves were often unreliable, thus hampering communication. French tanks were also very slow in speed in comparison to the Panzers (except for the Somua S-35), as they were designed as infantry support, enabling German tanks to offset their disadvantages by outmanoeuvring the French on the battlefield. In 1940, French military theoreticians still considered tanks as infantry support. As a consequence, at various points in the campaign, the French were not able to react as quickly as German armour.

In operational terms, the French did not seem to give much thought to armoured units as offensive weapons. Although some people such as Colonel de Gaulle tried during the 1930s to convince French High Command of the necessity to form armoured divisions supported by aviation and infantry, military conservatism prevented these "new ideas" from emerging. The French High Command was still obsessed with holding the front as it had in 1914–1918. The state of training was also unbalanced, with the majority of personnel trained only to man static fortifications. Minimal training for mobile actions was carried out between September 1939 and May 1940.

Deployment

The French forces in the north had three Army Groups. The 2nd and 3rd Army Groups defended the Maginot Line to the east; the 1st Army Group under Gaston-Henri Billotte was situated in the west and would execute the movement forward into the Low Countries.

Initially positioned on the left flank near the coast, the French 7th Army, reinforced by a light mechanised (armoured) division (Division Légère Mécanisée, or DLM), was intended to move to the Netherlands via Antwerp. Next to the south were the divisions of the British Expeditionary Force (BEF), which would advance to the Dyle Line and position itself to the right of the Belgian army, from Louvain to Wavre. The French 1st Army, reinforced by two light mechanised divisions and with a "reserve armoured division" (DCR) in reserve, would defend the Gembloux Gap between Wavre and Namur. The southernmost army involved in the move forward into Belgium was the French 9th Army, which had to cover the entire Meuse sector between Namur and Sedan.

The French 2nd Army would form the "hinge" of the movement and remain entrenched. It was to face the concentration of the elite German armoured divisions attack at Sedan. It was given low priority in manpower, anti-aircraft and anti-tank weapons and air support, and consisted of just five divisions. Two of these were over-age reservist units, or "Serie B" divisions, and one was a West African unit from Senegal. They had to cover a considerably larger front than they should have, considering their training and equipment, and thus formed the weak point of the French defence system. This stemmed from the French High Command's belief that the Ardennes forest was impassable to tanks, even though intelligence from the Belgian army and from their own intelligence services warned them of long armour and transport columns crossing the Ardennes and being stuck in a huge traffic-jam for some time. The French High Command simply refused to believe this was of any importance, as it did not suit their convictions on the matter.

Air forces

In the air, the Allies were numerically inferior: the French Armée de l'Air had 1,562 aircraft, and RAF Fighter Command committed 680 machines, while RAF Bomber Command could contribute some 392 aircraft to operations. Most of the Allied aircraft were obsolete types, such as the Morane-Saulnier M.S.406. In the fighter force, only the British Hawker Hurricane and the French Dewoitine D.520 could contend with the German Messerschmitt Bf 109, the D.520 having better manoeuvrability although being slightly slower. On 10 May 1940, though, only 36 D.520 fighters had been dispatched, all to one squadron. In fighter aircraft, the Allies had the numerical advantage; 836 German Bf 109s against 81 Belgian, 261 British and 764 French fighters of various types. The French and British also had larger aircraft reserves. In early June 1940, the French aviation industry had reached a considerable output, with an estimated matériel reserve of nearly 2,000 aircraft.

However, a chronic lack of spare parts crippled this fleet. Only 29% (599) of the aircraft were serviceable, of which 170 were bombers. Low serviceability meant the Germans had a clear numerical superiority in medium bomber aircraft, with six times as many as the French.

Despite its disadvantages the Armee de l'Air performed far better than expected, destroying 916 enemy aircraft in air to air combat during the Battle of France, for a kill ratio of 2.35:1; with almost a third of those kills accomplished by French pilots flying the US built Hawk 75 which accounted for 12.6% of the French single-seat fighter force.

Anti-aircraft defences

In addition to 580 13 mm (0.5 in) machine guns assigned to civilian defence, the French Army had 1,152 25 mm (0.98 in) anti-aircraft guns, with 200 20 mm (0.79 in) autocannons in the process of delivery, and 688 75 mm (2.95 in) guns and 24 90 mm (3.54 in) guns, the latter having problems with barrel wear. There were also 40 First World War-vintage 105 mm (4.1 in) anti-aircraft guns available. The BEF had 10 regiments of 3.7 in (94 mm) guns, then the most advanced heavy anti-aircraft weapon in the world, and seven and a half regiments of 40 mm (1.57 in) Bofors: with either three or four batteries per regiment, this represented roughly 300 heavy and 350 light AA guns. The Belgians had two heavy anti-aircraft regiments and were in the process of introducing 40 mm (1.57 in) Bofors guns as equipment for divisional anti-aircraft troops. The Dutch had 84 75 mm (2.95 in), 39 elderly 60 mm (2.36 in), seven 100 mm (3.9 in), and 232 20 mm (0.79 in) and 40 mm (1.57 in) anti-aircraft guns, and several hundred First World War-vintage Spandau M.25 machine guns on anti-aircraft mountings.

Fall Gelb

Northern front

Germany initiated Fall Gelb on the evening prior to and the night of 10 May. During the late evening of 9 May, German forces occupied Luxembourg. Army Group B launched its feint offensive during the night into the Netherlands and Belgium. During the morning of 10 May, Fallschirmjäger (paratroopers) from the 7th Flieger and 22. Luftlande Infanteriedivision under Kurt Student executed surprise landings at The Hague, on the road to Rotterdam and against the Belgian fort at Eben-Emael in order to facilitate Army Group B's advance.

The French command reacted immediately, sending its 1st Army Group north in accordance with Plan D. This move committed their best forces, diminishing their fighting power by the partial disorganisation it caused and their mobility by depleting their fuel stocks. By the time the French 7th Army crossed the Dutch border, they found the Dutch already in full retreat, and withdrew into Belgium to protect Brussels.

The Netherlands

The Luftwaffe was guaranteed air superiority over the Netherlands by sheer numerical superiority. They allocated 247 medium bombers, 147 fighter aircraft, 424 Junkers Ju 52 transports, and 12 Heinkel He 59 seaplanes to operations over the Netherlands. The Dutch Air Force, the Militaire Luchtvaartafdeling (ML), had a strength of 144 combat aircraft, half of which were destroyed within the first day of operations. The remainder was dispersed and accounted for only a handful of Luftwaffe aircraft shot down. In total the ML flew a mere 332 sorties, losing 110 of its aircraft.

The German 18. Armee secured all the strategically vital bridges in and toward Rotterdam, which penetrated Fortress Holland and bypassed the New Water Line from the south. However, an operation organised separately by the Luftwaffe to seize the Dutch seat of government, known as the Battle for The Hague, ended in complete failure. The airfields surrounding the city (Ypenburg, Ockenburg, and Valkenburg) were taken with heavy casualties and transport aircraft losses. Some 96 aircraft in all were lost to Dutch shell fire. The Luftwaffe''s Transportgruppen operations had cost it 125 Ju 52s destroyed and 47 damaged, representing 50% of the fleet's strength. Moreover, the airborne operation had cost the German paratroopers 4,000 men, of whom 1,200 were prisoners of war, out of 8,000. The Dutch evacuated them back to Britain. The total percentage cost of the defeat was 20% of NCOs and men and 42% of German officers were lost.

The French 7th Army failed to block the German armoured reinforcements from the 9. Panzerdivision, which reached Rotterdam on 13 May. That same day in the east, following the Battle of the Grebbeberg in which a Dutch counter-offensive to contain a German breach had failed, the Dutch retreated from the Grebbe line to the New Water Line. The Dutch Army, still largely intact, surrendered in the evening of 14 May after the Bombing of Rotterdam by the Luftwaffe. Heinkel He 111 medium bombers of Kampfgeschwader 54 (Bomber Wing 54) destroyed the centre of the city, an act which has remained controversial. The Dutch Army considered its strategic situation to have become hopeless and feared further destruction of the major Dutch cities. The capitulation document was signed on 15 May. However, Dutch forces continued fighting in Zeeland and the colonies while Queen Wilhelmina established a government in exile in Britain. Dutch casualties amounted to 2,157 army, 75 air force, and 125 Navy personnel. 2,559 civilians were also killed.

Invasion of Belgium

The Germans were able to establish air superiority in Belgium. Having completed thorough photographic reconnaissance missions, they destroyed 83 of the 179 aircraft of the Aeronautique Militaire within the first 24 hours. The Belgians would fly 77 operational missions but would contribute little to the air campaign. The Luftwaffe was assured air superiority over the Low Countries.

Because Army Group B had been so weakened compared to the earlier plans, the feint offensive by the German 6. Armee was in danger of stalling immediately, since the Belgian defences on the Albert Canal position were very strong. The main approach route was blocked by Fort Eben-Emael, a large fortress then generally considered the most modern in Europe, which controlled the junction of the Meuse and the Albert Canal. Any delay might endanger the outcome of the entire campaign, because it was essential that the main body of Allied troops was engaged before Army Group A established bridgeheads. To overcome this difficulty, the Germans resorted to unconventional means in the assault on the fort. In the early hours of 10 May, DFS 230 gliders landed near the fort and unloaded assault teams that disabled the main gun cupolas with hollow charges. The bridges over the canal were seized by German paratroopers. The Belgians launched considerable counterattacks which were broken up by the Luftwaffe. Shocked by a breach in its defences just where they had seemed the strongest, the Belgian Supreme Command withdrew its divisions to the KW-line five days earlier than planned. Similar operations against the bridges in the Netherlands, at Maastricht, failed. All were blown up by the Dutch and only one railway bridge was taken. This stalled the German armour on Dutch territory for a time.

The BEF and the French First Army were not yet entrenched, and the news of the defeat on the Belgian border was unwelcome. The Allies had been convinced Belgian resistance would have given them several weeks to prepare a defensive line at the Gembloux Gap. When General Erich Hoepner's XVI Panzerkorps, consisting of 3rd and 4th Panzer Divisions, was launched over the newly captured bridges in the direction of the Gembloux Gap, this seemed to confirm the expectations of the French Supreme Command that the German Schwerpunkt would be at that point. Gembloux was located between Wavre and Namur, on flat, ideal tank terrain. It was also an unfortified part of the Allied line. In order to gain time to dig in there, René Prioux, commanding the Cavalry Corps of the French 1st Army, sent two French Light Mechanised divisions, the 2nd DLM and 3rd DLM, forward to meet the German armour at Hannut, east of Gembloux. They would provide an advanced guarding screen which would stall the Germans and allow sufficient time for the French 1st Army to dig into formidable positions.

Battle of Hannut and Gembloux

The resulting Battle of Hannut, which took place on 12–13 May, was the largest tank battle until that date, with about 1,500 armoured fighting vehicles participating. The French disabled about 160 German tanks for the loss of 91 Hotchkiss H35 and 30 Somua S35 tanks destroyed or captured. The Germans controlled the battlefield after a voluntary French withdrawal. They recovered and eventually repaired or rebuilt many of their knocked-out tanks so German irreparable losses amounted to just 49 tanks (20, 3rd Panzer and 29, 4th Panzer). Prioux had achieved his mission in stalling the Panzers and allowing the French 1st Army to settle, so it was a strategic victory for the French. By contrast, although Hoepner had succeeded in diverting the French First Army from Sedan, which was his most important mission, he failed to destroy or forestall it. The French would escape the encirclement and still render invaluable support to the British Army in Dunkirk just two weeks later.

On 14 May, having been stalled at Hannut, Hoepner tried to break the French line again, against orders, leading to The Battle of the Gembloux Gap. This was the only time in the campaign when German armour frontally attacked a strongly held fortified position. The attempt was repelled by the 1st Moroccan Infantry Division, costing 4. Panzerdivision another 42 tanks, 26 of which were irreparable. This French defensive success was made irrelevant by events further south. Following the battle with the French 1st Army on 15 May, the war diary of the 4. Panzerdivision noted irreparable losses that day of nine Panzer Is, nine Panzer IIs, six Panzer IIIs, eight Panzer IVs, and two command tanks; of an original total of 314. 137 machines, of which 20 were mk IIIs and four were mk IVs, remained combat-ready.

Central front

Belgian and French Ardennes

In the centre, the progress of German Army Group A was to be delayed by Belgian motorised infantry and French mechanised cavalry divisions (Divisions Légères de Cavalerie) advancing into the Ardennes. The main resistance came from the Belgian 1st Chasseurs Ardennais along with the 5th French Light Cavalry Division (DLC). These forces had insufficient anti-tank capacity to block the surprisingly large number of German tanks they encountered and quickly gave way, withdrawing behind the Meuse. The German advance was greatly hampered by the sheer number of troops trying to force their way along the poor road network. Kleist's Panzergruppe had more than 41,000 vehicles. This huge armada had been allocated only four march routes through the Ardennes. The time-tables proved to be wildly optimistic and there was soon heavy congestion, beginning well over the Rhine to the east, which would last for almost two weeks. This made Army Group A very vulnerable to French air attacks, but these did not materialise. Although Gamelin was well aware of the situation, the French bomber force was far too weak to challenge German air superiority so close to the German border. The French had tried in vain to stem the flow of the German armour during the Battle of Maastricht and had failed with heavy losses. In two days, the bomber force had been reduced from 135 to 72.

On 11 May, Gamelin had ordered reserve divisions to begin reinforcing the Meuse sector. Because of the danger the Luftwaffe posed, movement over the rail network was limited to night-time, slowing the reinforcement, but the French felt no sense of urgency as they believed the build-up of German divisions would be correspondingly slow. The French Army did not conduct river crossings unless assured of heavy artillery support. While they were aware that the German tank and infantry formations were strong, they were confident in their strong fortifications and artillery superiority. However, the quality of the fighting men was dubious. The German advance forces reached the Meuse line late in the afternoon of 12 May. To allow each of the three armies of Army Group A to cross, three major bridgeheads were to be established; at Sedan in the south, Monthermé to the northwest and Dinant further to the north. The first German units to arrive hardly had local numerical superiority; their already insufficient artillery support was further limited by an average supply of just 12 rounds per gun. Fortunately for the German divisions, the French artillery was also limited to a daily combat supply rate of 30 rounds per "tube" (gun).

Battle of Sedan

At Sedan, the Meuse Line consisted of a strong defensive belt 6 km (3.7 mi) deep, laid out according to the modern principles of zone defence on slopes overlooking the Meuse valley and strengthened by 103 pillboxes, manned by the 147th Fortress Infantry Regiment. The deeper positions were held by the 55th Infantry Division. This was only a grade "B" reserve division. On the morning of 13 May, the 71st Infantry Division was inserted to the east of Sedan, allowing 55th Infantry to narrow its front by one-third and deepen its position to over 10 km (6.2 mi). Furthermore, it had a superiority in artillery to the German units present.

On 13 May, the German XIX Korps forced three crossings near Sedan, executed by the 1., 2. and 10. Panzerdivisions, reinforced by the elite Großdeutschland infantry regiment. Instead of slowly massing artillery as the French expected, the Germans concentrated most of their air power (as they lacked strong artillery forces) to smash a hole in a narrow sector of the French lines by carpet bombing and by dive bombing. Hermann Göring had promised Guderian that there would be extraordinarily heavy air support during a continual eight-hour air attack, from 08:00 am until dusk. The Luftwaffe executed the heaviest air bombardment the world had yet witnessed and the most intense by the Germans during the war. The Luftwaffe committed two Sturzkampfgeschwader (Dive Bomber Wings) to the assault, flying 300 sorties against French positions. A total of 3,940 sorties were flown by nine Kampfgeschwader (Bomber Wings).

Some of the forward pillboxes were unaffected and repulsed the crossing attempts of the 2. and 10. Panzerdivisions. The morale of the deeper units of the 55th Infantry, however, had been broken by the affect of the air attacks. The French supporting artillery batteries had fled. The German infantry, at a cost of a few hundred casualties, had penetrated up to 8 km (5.0 mi) into the French defensive zone by midnight. Even by then most of the infantry had not crossed, much of the success being due to the actions of just six platoons, mainly assault engineers.

The disorder that had begun at Sedan spread down the French lines. At 19:00 on 13 May, the 295th regiment of 55th Infantry Division, holding the last prepared defensive line at the Bulson ridge 10 km (6.2 mi) behind the river, was panicked by the false rumour that German tanks were already behind its positions. It fled, creating a gap in the French defences, before even a single German tank had crossed the river. This "Panic of Bulson" also involved the divisional artillery. The Germans had not attacked their position, and would not do so until 12 hours later, at 07:20 on 14 May. Still, the French had several hours to launch a counter offensive before the Germans consolidated the bridgeheads, but failed to attack soon enough.

Recognising the gravity of the defeat at Sedan, General Gaston-Henri Billotte, commander of the 1st Army Group, whose right flank pivoted on Sedan, urged that the bridges across the Meuse be destroyed by air attack, convinced that "over them will pass either victory or defeat!". That day, every available Allied light bomber was employed in an attempt to destroy the three bridges, but failed to hit them while suffering heavy losses. Some 44% of the Allies' bomber strength was destroyed.

Collapse of the Meuse front

Heinz Guderian, the commander of the German XIX. Armeekorps, had indicated on 12 May that he wanted to enlarge the bridgehead to at least 20 km (12 mi). His superior, Ewald von Kleist, ordered him on behalf of Hitler to limit his moves to a maximum of 8 km (5.0 mi) before consolidation. At 11:45 on 14 May, von Rundstedt confirmed this order, which implied that the tanks should now start to dig in. Guderian was able to get to Ewald von Kleist to agree to "reconnaissance in force", by threatening to resign and behind the scenes interventions. This vague terminology allowed Guderian to move forward, effectively ignoring Ewald von Kleist's order to halt.

In the original von Manstein Plan as Guderian had suggested, secondary attacks would be carried out to the southeast, in the rear of the Maginot Line, to confuse the French command. This element had been removed by Halder but Guderian now sent the 10th Panzerdivision and Großdeutschland infantry regiment south to execute precisely such a feint attack, using the only available route south over the Stonne plateau. The commander of the French 2nd Army, General Charles Huntziger, intended to carry out a counterattack at the same spot by the armoured 3e Division Cuirassée de Réserve (DCR) to eliminate the bridgehead. This resulted in an armoured collision, both parties trying in vain to gain ground in furious attacks from 15–17 May, the village of Stonne changing hands many times. Huntzinger considered this at least a defensive success and limited his efforts to protecting his flank. Holding Stonne and taking Bulson would have enabled the French to hold onto the high ground overlooking Sedan. They could disrupt the Sedan bridgehead, even if they could not take it. Heavy battles took place and Stonne changed hands 17 times. It fell to the Germans for the last time on the evening of 17 May.

Guderian, meanwhile, had turned his other two armoured divisions, the 1. and 2. Panzerdivisions, sharply to the west on 14 May. They began to advance at speed to the English Channel.

On 15 May, in heavy fighting, Guderian's motorised infantry dispersed the reinforcements of the newly formed French 6th Army in their assembly area west of Sedan, undercutting the southern flank of the French 9th Army. The 9th Army collapsed and surrendered en masse. The 102nd Fortress Division, its flanks unsupported, was surrounded and destroyed on 15 May at the Monthermé bridgehead by the 6. and 8. Panzerdivisions acting without air support. The French 2nd Army had also been seriously mauled and had rendered itself impotent. The 9th Army was giving way because they also did not have time to fortify their lines. Erwin Rommel had breached its defences within 24 hours of its conception. This allowed Rommel to break free with his 7th Panzer Division, refusing to allow his division rest and advancing both by day and night. The Ghost division advanced 30 mi (48 km) in just 24 hours.

Rommel's lines of communication with his superior, General Hermann Hoth, and his headquarters were cut. Disobeying orders and not waiting for the French to establish a new line of defence, he continued to advance north-west to Avesnes-sur-Helpe, just ahead of the 1. and 2. Panzerdivisions. Rommel was lucky, because the French 5th Motorised Infantry Division had set up its overnight bivouac in his path, leaving its vehicles neatly lined up along the roadsides. Rommel's tanks dashed right through them. The slow speed, overloaded crews and lack of any means of communication in battle undid the French. The 5th Panzer Division joined in the fight. The French did inflict significant losses on the division but they could not cope with the speed of the German mobile units, which closed fast and destroyed the French armour at close range. During this battle, the remaining elements of the 1st DCR, resting after losing all but 16 of its tanks in Belgium, were also engaged and defeated. The French unit retreated, with just three remaining tanks. The 1st DCR was effectively destroyed on 17 May. The Germans lost 50 out of 500 tanks in the battle.

By 17 May, Rommel claimed to have taken 10,000 prisoners and suffered only 36 losses. Guderian was delighted with the fast advance, and encouraged his XIX Korps, consisting of the 1., 2. and 10. Panzerdivisions to head for the channel, continuing until fuel was exhausted. However, the success of his commanders on the ground began to have effects on Hitler who worried that the German advance was moving too fast. Halder recorded in his diary on 17 May that "Fuhrer is terribly nervous. Frightened by his own success, he is afraid to take any chance and so would pull the reins on us ... [he] keeps worrying about the south flank. He rages and screams that we are on the way to ruin the whole campaign." Through deception and different interpretations of orders to stop from Hitler and von Kleist, the commanders on the ground were able to ignore Hitler's attempts to stop the northern advance to the sea.

Low French morale

The Panzerkorps now slowed their advance considerably and put themselves in a very vulnerable position. They were stretched out, exhausted, low on fuel, and many tanks had broken down. There was now a dangerous gap between them and the infantry. A determined attack by a fresh and large enough mechanised force might have cut the Panzers off and wiped them out.

The French High Command, already contemplatively ponderous and sluggish via its firm espousing of the broad strategy of "methodological warfare", however, was reeling from the shock of the sudden offensive and was now stung by a sense of defeatism. On the morning of 15 May, French Prime Minister Paul Reynaud telephoned the new Prime Minister of the United Kingdom Winston Churchill and said "We have been defeated. We are beaten; we have lost the battle." Churchill, attempting to offer some comfort to Reynaud, reminded the Prime Minister of all the times the Germans had broken through the Allied lines in World War I only to be stopped. Reynaud was, however, inconsolable.

Churchill flew to Paris on 16 May. He immediately recognised the gravity of the situation when he observed that the French government was already burning its archives and was preparing for an evacuation of the capital. In a sombre meeting with the French commanders, Churchill asked General Gamelin, "Où est la masse de manoeuvre?" ["Where is the strategic reserve?"] that had saved Paris in the First World War. "Aucune" ["There is none"] Gamelin replied. After the war, Gamelin claimed his response was "There is no longer any." Churchill described hearing this later as the single most shocking moment in his life. Churchill asked Gamelin where and when the general proposed to launch a counterattack against the flanks of the German bulge. Gamelin simply replied "inferiority of numbers, inferiority of equipment, inferiority of methods".

Failed Allied counter-attacks

Some of the best Allied units in the north had seen little fighting. Had they been kept in reserve they might have been used in a decisive counter-strike. In a twist of irony, pre-war General Staff Studies had asserted the main reserves were to be kept on French soil, to resist an invasion of the Low Countries, deliver a counterattack or "re-establish the integrity of the original front".

Despite having a numerically superior armoured force, the French failed to use it properly, or to deliver an attack on the vulnerable German bulge. The Germans combined their fighting vehicles in major, operational formations and used them at the point of main effort. The bulk of French armour was scattered along the front in tiny formations. Most of the French reserve divisions had by now been committed. The 1st DCR had been wiped out when it had run out of fuel and the 3rd DCR had failed to take its opportunity to destroy the German bridgeheads at Sedan. The only armoured division still in reserve, 2nd DCR, was to attack on 16 May west of Saint-Quentin, Aisne. The division's commander could locate only seven of its 12 companies, which were scattered along a 49 mi × 37 mi (79 km × 60 km) front. The formation was overrun by the 8. Panzerdivision while still forming up and was effectively destroyed as a fighting unit.

Colonel Charles de Gaulle, in command of France's hastily formed 4th DCR, attempted to launch an attack from the south at Montcornet where Guderian had his Korps headquarters and the 1. Panzerdivision had its rear service areas. During the Battle of Montcornet Germans hastily improvised a defence while Guderian rushed up the 10. Panzerdivision to threaten De Gaulle's flank. This flank pressure and attacks by the Luftwaffe's VIII Fliegerkorps broke up the attack. French losses on 17 May were 32 tanks and armoured vehicles, but had "inflicted loss on the Germans". On 19 May, after receiving reinforcements, De Gaulle made another effort, and was repulsed with the loss of 80 of 155 vehicles. von Richthofen's Fliegerkorps VIII had done most of the work, by targeting French units moving into position to attack the vulnerable German flanks it was able to stop most counterattacks from starting. The defeat of de Gaulle's unit and the disintegration of the French 9th Army was caused mainly by Richthofen's air units.

Although De Gaulle had achieved a measure of success, his attacks on 17 and 19 May did not significantly alter the overall situation. It was the only French counter-attack on the German forces advancing to the channel.

German spearheads reach the Channel

The Allies did little to either threaten the Panzerkorps or to escape from the danger that they posed. The Panzer troops used 17–18 May to refuel, eat, sleep and return more tanks to working order. On 18 May, Rommel caused the French to give up Cambrai by merely feinting an armoured attack toward the city.

On 19 May, General Edmund Ironside, the British Chief of the Imperial General Staff, conferred with General Lord Gort, commander of the BEF, at his headquarters near Lens. He urged Gort to save the BEF by attacking south-west toward Amiens. Gort replied that seven of his nine divisions were already engaged on the Scheldt River, and he had only two divisions left with which he would be able to mount such an attack. Ironside then asked Gort under whose command he was acting. Gort replied that this was General Billotte, the commander of the French 1st Army Group, but that Billotte had issued no orders for eight days. Ironside confronted Billotte, whose own headquarters was nearby, and found him apparently incapable of taking decisive action. He returned to Britain concerned that the BEF was already doomed, and ordered urgent anti-invasion measures.

The German land forces could not remain inactive any longer since it would allow the Allies to reorganise their defence or escape. On 19 May, Guderian was permitted to start moving again and smashed through the weak British 18th and 23rd Territorial Divisions located on the Somme river. The German units occupied Amiens and secured the westernmost bridge over the river at Abbeville. This move isolated the British, French, Dutch, and Belgian forces in the north. On 20 May, a reconnaissance unit from Rudolf Veiel's 2. Panzerdivision reached Noyelles-sur-Mer, 100 kilometres (62 mi) to the west of their positions on the 17th. From there, they were able to see the Somme estuary and the English Channel. A huge pocket, containing the Allied 1st Army Group (the Belgian, British, and French 1st, 7th and 9th Armies), was created.

VIII. Fliegerkorps, under the command of Wolfram von Richthofen, covered the dash to the channel coast. Heralded as the Ju 87s' (Stuka) "finest hour", these units responded via an extremely efficient communications system to the Panzer Divisions' every request for support, which effectively blasted a path for the Army. The Ju 87s were particularly effective at breaking up attacks along the flanks of the German forces, breaking fortified positions, and disrupting rear-area supply chains. The Luftwaffe also benefitted from excellent ground-to-air communications throughout the campaign. Radio-equipped forward liaison officers could call upon the Stukas and direct them to attack enemy positions along the axis of advance. In some cases, the Luftwaffe responded to requests in 10–20 minutes. Oberstleutnant Hans Seidemann (Richthofen's Chief of Staff) said that "never again was such a smoothly functioning system for discussing and planning joint operations achieved". Closer examination reveals the army had to wait 45–75 minutes for Ju 87 units, and just 10 minutes for the Henschel Hs 123 units.

Weygand Plan

On the morning of 20 May, Maurice Gamelin ordered the armies trapped in Belgium and northern France to fight their way south and link up with French forces that would be pushing northward from the Somme river. However on the evening of 19 May, French Prime Minister Paul Reynaud had dismissed Gamelin for his failure to contain the German offensive, and replaced him with Maxime Weygand. Weygand had little sense of urgency. He claimed his first mission as Commander-in-Chief would be to get a good night's sleep. Weygand was guilty of wasting valuable time, time which was needed to form a quick and powerful counter-attack. He cancelled Gamelin's planned offensive, then wasted several days making courtesy visits to dignitaries in Paris. He then ordered a similar plan to Gamelin's, proposing a counter-offensive from the north and south against the German "corridor", which entailed a combined thrust by the encircled armies in the pocket and French forces on the Somme front (the newly created French 3rd Army Group, under the command of General Antoine-Marie-Benoît Besson). The situation demanded an all-out offensive on the corridor.

On 22 May, Weygand ordered his forces to pinch off the German armoured spearhead by combining attacks from the north and the south. On the map, this seemed like a feasible mission, as the corridor through which von Kleist's two Panzer Corps had moved to the coast was narrow. On paper, Weygand had sufficient forces to execute it: to the north were the three DLM and the BEF; to the south, was de Gaulle's 4th DCR. However, while the German position was far from safe, the opportunity had been lost. The delays had allowed the Germans to push more infantry divisions into the corridor and they had pushed further along the channel coast. Weygand flew into the pocket on 21 May and met General Billotte, commander of the First Army Group, and King Leopold III of Belgium. The Belgian position on any offensive move was made clear by Leopold. As far as he was concerned, the Belgian Army could not conduct offensive operations as it lacked tanks and aircraft; it existed solely for defence. The King also made clear that in the rapidly shrinking area of Belgium still free, there was only enough food for two weeks. Leopold did not expect the BEF to jeopardise its own position in order to keep contact with the Belgian Army, but he warned the British that if it persisted with the southern offensive the Belgians would be overstretched and their army would collapse. King Leopold suggested the best recourse was to establish a beach-head covering Dunkirk and the Belgian channel ports.

Gort doubted the French Army's ability to prevail in the offensive. On 23 May, making matters worse, Billotte was killed in a road traffic accident, leaving the Allied First Army Group in the pocket leaderless for three days. Billotte was the only member of the Allied armies thoroughly informed on the Weygand plan's details. The same day, the British decided to evacuate from the Channel ports. In the event, communications broke down and only two minor offensives, by the British and French at Arras on 21 May and by the French at Cambrai on 22 May, would be acted upon.

Major-General Harold Franklyn, commanding two tank battalions, had moved into the Arras area. Franklyn was not aware of a French push north toward Cambrai, and the French were unaware of a British attack heading south, out of the pocket, toward Arras. Ignorant as to the importance of the operation, Franklyn assumed he was to relieve the Allied garrison at Arras and to sever German communications in the immediate area. He did not therefore want to risk throwing his main units, the 5th and 50th Infantry Divisions into the fight, especially if the objectives were limited. He also had the French 3rd DLM available, from the French 1st Army. It had caused the German armour severe trouble at the Battle of Hannut with its SOMUA S35 heavy tanks. They were given no more than a flank protection role. Only two infantry battalions and two tank battalions were made available for the attack. British armour numbers had dwindled owing to mechanical failures. However they still fielded 74 Matilda tanks and 14 light tanks.

The resulting Battle of Arras achieved surprise and initial success against German forces which were stretched, but it still failed. Radio communication between tanks and infantry was poor and there was little combined arms coordination as practiced by the Germans. In the end, hastily set up German defences (including 88 mm (3.46 in) FlaK guns and 105 mm (4.1 in) field guns) stopped the attack. The French inflicted heavy losses on German armour as they retreated, but the Luftwaffe broke up the counter-attacks. Just 28 of the 88 British tanks survived. The French V Corps' attack at Cambrai also failed. V Corps had been too disorganised after previous fighting in Belgium to launch a serious effort.

Although this attack was not part of any coordinated attempt to destroy the Panzerkorps, the German High Command panicked even more than Rommel. They thought that hundreds of Allied tanks were about to smash into their elite forces. It was unjustified panic. The operational and strategic effects of the British attack was out of proportion to its tactical achievements. On the morning of the 22 May, the German High Command had regained confidence and ordered Guderian's XIX Panzerkorps to press north and push on to the Channel ports: the 1. Panzerdivision to Calais, the 2. Panzerdivision to Boulogne and the 10. Panzerdivision to Dunkirk. Later, the missions of the 1st and 10. Panzerdivisions were reversed. The 1. Panzer was ordered to Dunkirk while the 10. Panzer was to take Calais.

Although De Gaulle launched some ineffectual counterattacks around Peronne on 19 May, the attack from the south was launched only on 23 May, when 7th DIC, supported by a handful of tanks, failed to retake Amiens. On 27 May, the British 1st Armoured Division, hastily brought over from England, attacked Abbeville in force but was beaten back with crippling losses. The next day de Gaulle tried again with the same result. But, by now, even complete success very well might not have saved the Allied forces in the north.

BEF and the Channel ports

Battle of Calais

In the early hours of 23 May, Gort ordered a retreat from Arras. By now, he had no faith in the Weygand plan, nor in Weygand's proposal to at least try to hold a pocket on the Flemish coast, a so-called Réduit de Flandres. Gort knew that the ports needed to supply such a foothold were already being threatened. That same day, the 2. Panzer Division had assaulted Boulogne. The British garrison there surrendered on 25 May, although 4,286 men were evacuated by Royal Navy ships. The RAF also provided air superiority over the port, denying the Luftwaffe an opportunity to attack the shipping.

The 10. Panzerdivision, commanded by Ferdinand Schaal, attacked Calais on 24 May. British reinforcements (the 3rd Royal Tank Regiment, equipped with cruiser tanks, and the 30th Motor Brigade) had been hastily landed 24 hours before the Germans attacked. The defenders held on to the port as long as possible, aware that an early capitulation would free up German forces to advance on Dunkirk. The British and French held the town despite the best efforts of Schaal's division to break through. Frustrated, Guderian ordered that if Calais had not fallen by 14:00 on 26 May, he would withdraw the 10. Panzer division and ask the Luftwaffe to destroy the town. Eventually, the French and British ran out of ammunition and the Germans were able to break into the fortified city at around 13:30 on 26 May 30 minutes before Schaal's deadline was up. Despite the French surrender of the main fortifications, the British held the docks until the morning of 27 May. Around 440 men were evacuated. The Siege of Calais lasted for four crucial days. However, the delaying action came at a price. Some 60% of Allied personnel were killed or wounded.

Halt order

On 23 May, Günther von Kluge proposed that the German 4. Armee, which was poised to continue the attack against the Allied forces at Dunkirk, should "halt and close up". Seeing the Allies were trapped in the city, Gerd von Rundstedt agreed with von Kluge. In the 4. Armee diary, it is recorded on 23 May "will, in the main, halt tomorrow [May 24] in accordance with Colonel-General von Rundstedt's order." General Walther von Brauchitsch, commander in chief of the German Army, disagreed with his colleagues and wanted to continue the attack against Dunkirk by putting the 4. Armee under Bock. Bock was busy and Halder agreed with Von Rundstedt and with von Kluge to stop action against Dunkirk. The disagreement went to Hitler, who overruled Brauchitsch and agreed with stopping action against Dunkirk. Hitler's error wasn't in making the command to halt the German army but in allowing the orders already drawn up by the German generals to stand. It appears that Kleist also agreed with the halt order, which Hitler "rubber-stamped". The halt order remains extremely controversial.

At the same time, Army Group B under Bock was stripped of most of its divisions, including its reserves and air support. Its complement shrank to just 21 divisions, while Army Group A swelled to 70 divisions, including all ten Panzer Divisions. Army Group B was to be used as a "hammer" against Army Group A's "anvil". Halder later claimed Hitler's motivation for the transfer was his wish that the decisive battle be fought on French, not Flemish soil.

Hermann Göring convinced Hitler that the Luftwaffe could prevent any evacuation and von Rundstedt warned him that any further effort by the armoured divisions would lead to a much longer refitting period. The delay and failure of the Luftwaffe to stop the evacuation wasted some three days (24–27 May) and allowed the Allies to build a defence to the approaches of Dunkirk, the main evacuation port. It would seem that Hitler, Göring and Rundstedt shared responsibility for the mistake.

Operation Dynamo

The Allies launched Operation Dynamo which evacuated the encircled British, French and Belgian troops from the northern pocket in Belgium and Pas-de-Calais, beginning on 26 May. About 28,000 men were evacuated on the first day. The French 1st Army—the bulk of which remained in Lille—owing to Weygand's failure to pull it back along with other French forces to the coast, mounted a long defence of the city, the 50,000 men finally capitulating on 31 May. While the 1st Army was mounting its sacrificial defence at Lille, it drew German forces away from Dunkirk, allowing 70,000 Allied soldiers to escape. Total Allied evacuation rates stood at 165,000 on 31 May. The Allied position was complicated by Belgian King Léopold III's surrender the following day, which was postponed until 28 May. The gap left by the Belgian Army stretched from Ypres to Dixmude. Nevertheless, a collapse was prevented and 139,732 British and 139,097 French soldiers were evacuated. Between 31 May and 4 June, some 20,000 British and 98,000 French had been saved. Still, some 30–40,000 French soldiers of the rearguard remained to be captured. The overall total evacuated was 338,226.

During the Dunkirk battle, the Luftwaffe did its best to prevent the evacuation. It flew 1,882 bombing and 1,997 fighter sorties. British losses totalled 6% of their total losses during the French campaign, including 60 precious fighter pilots. The Luftwaffe failed in its task of preventing the evacuation, but had inflicted serious losses on the Allied forces. A total of 89 merchantmen (of 126,518 grt) were lost; the Royal Navy lost 29 of its 40 destroyers sunk or seriously damaged. The Germans lost around 100 aircraft confirmed destroyed, and the RAF 106 fighters. Other sources put Luftwaffe losses in the Dunkirk area at 240.

Confusion still reigned. After the evacuation at Dunkirk and while Paris was enduring a short-lived siege, part of the 1st Canadian Infantry Division was sent to Brittany but was withdrawn after the French capitulation. The British 1st Armoured Division under General Evans, without its infantry which had earlier been diverted to the defence of Calais, had arrived in France in June 1940. It was joined by the former labour battalion of the 51st (Highland) Division and was forced to fight a rearguard action. At the end of the campaign, Erwin Rommel praised the staunch resistance of British forces, despite being under-equipped and without ammunition for much of the fighting.

On 26 February 1945, Hitler claimed he had let the BEF escape as a "sporting" gesture, in the hope Churchill would come to terms. Few historians accept Hitler's word in light of Directive No. 13, which called for "the annihilation of French, British and Belgian forces in the Dunkirk pocket".

Fall Rot

French problems

The best and most modern French armies had been sent north and lost in the resulting encirclement; the French had also lost much of their heavy weaponry and their best armoured formations. Overall, the Allies had lost 61 divisions in Fall Gelb. Weygand was faced with the prospect of defending a long front (stretching from Sedan to the Channel), with a greatly depleted French Army now lacking significant Allied support. Weygand had only 64 French and one remaining British division (the 51st Highland) available. Weygand lacked the reserves to counter a breakthrough or to replace frontline troops, should they become exhausted from a prolonged battle on a front of 965 kilometres. The Germans had 142 divisions to use.

Adding to this grave situation, on 10 June, Italy declared war on France and Britain. Italy was not prepared for war and made little impact during the last twelve days of fighting. Italian dictator Benito Mussolini was aware of this and sought to profit from German successes. Mussolini felt the conflict would soon end. As he said to the Army's Chief-of-Staff, Marshal Badoglio, "I only need a few thousand dead so that I can sit at the peace conference as a man who has fought." However, French General René Olry commanding the Army of the Alps resisted all Italian attacks, and then repulsed German attacks from the Rhone valley.

Collapse of the Weygand line

The Germans renewed their offensive on 5 June on the Somme. During the next three weeks, far from the easy advance the Wehrmacht expected, they encountered strong resistance from a rejuvenated French Army. It had fallen back on its communications, and had closer access to repair shops, supply dumps and stores. Moreover, 112,000 evacuated French soldiers were repatriated via the Normandy and Brittany ports. It was some substitute for the lost divisions in Flanders. The French were also able to make good a significant amount of its armoured losses and raised the 1st and 2nd DCR (heavy armoured divisions). De Gaulle's division—the 4th DCR—also had its losses replaced. Morale rose and was very high by the end of May 1940.

A central explanation for the high morale was threefold; most French soldiers that knew about the defeats, and were now joining the line, only knew of German success by hearsay; surviving French officers had increased tactical experience against German mobile units; increased confidence in their weapons after seeing their artillery, which the Wehrmacht post-battle analysis recognised as technically very good, and their tanks perform better in combat than the German armour. The French tanks were now known to have heavier armour and armament.

Between 23 and 28 May, they reconstituted the French 7th and 10th Armies. Weygand decided on hedgehog tactics, which were to implement defence in depth operations, and perform delaying strategies designed to inflict maximum attrition on enemy units. He employed units in towns and small villages, as well as major towns and cities, and fortified them 360° along their perimeter. Behind this, the new infantry, armoured, and half-mechanised divisions formed up, ready to counterattack and relieve the surrounded units, which were ordered to hold out at all costs.

Army Group B attacked either side of Paris. Of its 47 divisions it had the majority of the mobile units. In fact, only 48 hours into the offensive, the Germans had not made any major breakthroughs. The Germans had been "stopped in their tracks". On the Aisne, Erich Hoepner's XVI Panzerkorps employed over 1,000 AFVs, two Panzer Divisions and a motorised division against the French. The assault was crude, and Hoepner soon lost 80 out of 500 AFVs in the first attack. The German 4. Armee succeeded in capturing bridgeheads over the Somme river, but the Germans struggled to get over the Aisne. Weygand had organised a defence in depth and frustrated the crossing. In a series of examples at Amiens, the Germans were repeatedly driven back by powerful French artillery concentrations, and came to recognise improved French tactics. Once again, the German Army relied on the Luftwaffe to help decisively, by silencing French guns and enabling the German infantry to inch forward. German progress was made only late on the third day of operations, finally forcing crossings. The French Air Force attempted to bomb them but failed. German sources acknowledged the battle was, "hard and costly in lives, the enemy putting up severe resistance, particularly in the woods and tree lines continuing the fight when our troops had pushed passed the point of resistance". However, south of Abbeville, the French 10th Army under General Robert Altmayer had its front broken and it was forced to retreat to Rouen and south along the Seine river. The rapid German advances were the sign of a weakening enemy. Rommel and his 7. Panzerdivision headed west over the Seine river through Normandy and capturing the port of Cherbourg on 18 June. On the way to Cherbourg, Rommel forced the surrender of the British 51st (Highland) Division on 12 June. In close-quarter combat, the Luftwaffe was struggling to have an impact. However, in an operational sense, they helped disperse French armour. The German spearheads were overextended and vulnerable to counter strokes, but the concentration of the Luftwaffe denied the French the ability to concentrate, and the fear of air attack negated their mass and mobile use by Weygand.

On 10 June, the French government declared Paris an open city. The German 18. Armee now deployed against Paris. The French resisted the approaches to the capital strongly, but the line was broken in several places. Weygand now asserted it would not take long for the French Army to disintegrate. On 13 June, Churchill attended an Allied Supreme War Council Meeting at Tours. He suggested a union between the two countries. It was rejected. On 14 June, Paris fell. Those Parisians who stayed in the city found that in most cases the Germans were extremely well mannered.

On top of this added danger, the situation in the air had also grown critical. The Luftwaffe established air supremacy (as opposed to air superiority) as the French air arm was on the verge of collapse. The French Air Force (Armée de l'Air) had only just begun to make the majority of bomber sorties; between 5 and 9 June (during Operation Paula), over 1,815 missions, of which 518 were by bombers, were flown. The number of sorties flown declined as losses were now becoming impossible to replace. The RAF attempted to divert the attention of the Luftwaffe with 660 sorties flown against targets over the Dunkirk area but losses were heavy; on 21 June alone, 37 Bristol Blenheims were destroyed. After 9 June, French aerial resistance virtually ceased, some surviving aircraft withdrew to French North Africa. The Luftwaffe now "ran riot". Its attacks were focused on the direct and indirect support of the German Army. The Luftwaffe subjected lines of resistance to ferocious assault, which then quickly collapsed under armoured attack.

Collapse of the Maginot line

Meanwhile, to the east, Army Group C was to help Army Group A encircle and capture the French forces on the Maginot line. The goal of the operation was to envelop the Metz region, with its fortifications, in order to prevent a French counter offensive from the Alsace region against the German line on the Somme. Guderian's XIX Korps was to advance to the French border with Switzerland and trap the French forces in the Vosges Mountains while the XVI Korps attacked the Maginot Line from the west, into its vulnerable rear to take the cities of Verdun, Toul and Metz. The French, meanwhile, had moved the French 2nd Army Group from the Alsace and Lorraine to the 'Weygand line' on the Somme, leaving only small forces guarding the Maginot line. After Army Group B had begun its offensive against Paris and into Normandy, Army Groups A began its advance into the rear of the Maginot line. On 15 June, Army Group C launched Operation Tiger, a frontal assault across the Rhine river and into France.

German attempts to break open or into the Maginot line prior to Tiger had failed. One assault lasted for eight hours on the extreme north of the line, costing the Germans 46 dead and 251 wounded, while just two French were killed (one at Ferme-Chappy and one at Fermont fortress). On 15 June, the last well-equipped French forces, including the French 4th Army were preparing to leave as the Germans struck. The French now holding the line were skeletal. The Germans greatly outnumbered the French. They could call upon the I Armeekorps of seven divisions and 1,000 artillery pieces, although most were First World War vintage, and could not penetrate the thick armour of the fortresses. Only 88 mm guns could do the job, and 16 were allocated to the operation. To bolster this, 150 mm and eight railway batteries were also employed. The Luftwaffe deployed the V Fliegerkorps to give air support.

The battle was difficult and slow progress was made against strong French resistance. However, each fortress was overcome one by one. One fortress ( Schoenenbourg) fired 15,802 75 mm rounds at attacking German infantry. It was the most heavily shelled of all the French positions. Nevertheless, its armour protected it from fatal damage. The same day Tiger was launched, Operation Kleiner Bär began. Five assault divisions of the VII Armeekorps crossed the Rhine into the Colmar area with a view to advancing to the Vosges Mountains. It had 400 artillery pieces bolstered by heavy artillery and mortars. They drove the French 104th and 105th Divisions back into the Vosges Mountains on 17 June. However, on the same day Guderian's XIX Korps reached the Swiss border and the Maginot defences were cut off from the rest of France. Most units surrendered on 25 June, and the Germans claimed to have taken 500,000 prisoners. Some main fortresses continued the fight, despite appeals for surrender. The last only capitulated on 10 July, after a request from General Alphonse Joseph Georges, and only then under protest. Of the 58 major fortifications on the Maginot Line, just 10 were captured by the Wehrmacht in battle.

The second BEF evacuation

The evacuation of the second BEF took place during Operation Ariel between 15 and 25 June. The Luftwaffe, with complete domination of the French skies, was determined to prevent more Allied evacuations after the Dunkirk debacle. I. Fliegerkorps was assigned to the Normandy and Brittany sectors. On 9 and 10 June, the port of Cherbourg was subject to 15 tonnes of German bombs, whilst Le Havre received 10 bombing attacks which sank 2949 GRT of escaping Allied shipping. On 17 June, Junkers Ju 88s—mainly from Kampfgeschwader 30—sank a "10,000 tonne ship" which was the 16243 GRT liner RMS Lancastria off St Nazaire, killing some 4,000 Allied personnel. Nevertheless, the Luftwaffe failed to prevent the mass evacuation of some 190,000–200,000 Allied personnel.

Surrender and armistice

Discouraged by his cabinet's hostile reaction to a British proposal to unite France and Britain to avoid surrender, and believing that his ministers no longer supported him, Prime Minister Paul Reynaud resigned on 16 June. He was succeeded by Marshal Philippe Pétain, who delivered a radio address to the French people announcing his intention to ask for an armistice with Germany. When Hitler received word from the French government that they wished to negotiate an armistice, he selected the Compiègne Forest as the site for the negotiations.

Compiègne had been the site of the 1918 Armistice, which had ended the First World War with a humiliating defeat for Germany; Hitler viewed the choice of location as a supreme moment of revenge for Germany over France. The armistice was signed on 22 June 1940 in the very same railway carriage in which the 1918 Armistice was signed (it was removed from a museum building and placed on the precise spot where it was located in 1918), Hitler sat in the same chair in which Marshal Ferdinand Foch had sat when he faced the defeated German representatives. After listening to the reading of the preamble, Hitler, in a calculated gesture of disdain to the French delegates, left the carriage, leaving the negotiations to the Chief of Staff of the OKW, Wilhelm Keitel. The armistice and the cease-fire went into effect at 01:35 on 25 June.

Aftermath

France was divided into a German occupation zone in the north and west and a nominally independent state in the south. The new French state known as Vichy France, was headed by Pétain. Charles de Gaulle, who had been made an Undersecretary of National Defence by Reynaud in London at the time of the surrender, made his Appeal of 18 June in which he refused to recognise Pétain's Vichy government as legitimate and began the task of organising the Free French Forces.

The British doubted Admiral François Darlan's promise not to allow the French fleet at Toulon to fall into German hands by the wording of the armistice conditions. They feared the Germans would seize the French Navy's fleet, docked at ports in Vichy France and North Africa and use them in an invasion of Britain ( Operation Sea Lion). Within a month, the Royal Navy would attack the French naval forces which were stationed in North Africa. The British Chiefs of Staff Committee had concluded in May 1940 that if France collapsed, "we do not think we could continue the war with any chance of success" without "full economic and financial support" from the United States. Churchill's desire for American aid led in September to the Destroyers for Bases agreement that began the wartime Anglo-American partnership.

The occupation of the various zones continued until November 1942, when the Allies launched Operation Torch, the invasion of Western North Africa. To safeguard southern France, the Germans enacted Operation Anton, and occupied Vichy France. In June 1944, the Western Allies launched Operation Overlord. Followed by the smaller but easier Operation Anvil-Dragon on the French Mediterranean coast on 15 August. German troops in western and central France now run the risk of becoming cut off, and began to retire towards Germany, with the exceptions of the extremly fortified submarine bases at the French Atlantic coast, which remained in German hands until the German capitulation. On 24 August 1944 Paris was liberated, and by September most of the country was in Allied hands.

By the time of the liberation, some 580,000 French had been killed (Of these 40.000 were killed by the western Allied, during the bombardments of the first 48 hours of Operation Overlord). Military deaths were 92,000 in 1939–1940. Some 58,000 died from 1940 to 1945 fighting in the Free French forces. In Alsace-Lorraine province citizens joined the German Army. Some 40,000 became casualties. Civilian casualties amounted to around 150,000 (60,000 by aerial bombing, 60,000 in the resistance, and 30,000 murdered by German occupation forces). Prisoners of war and deportee totals were around 1,900,000. Of this, around 240,000 died in captivity. An estimated 40,000 were prisoners of war, 100,000 racial deportees, 60,000 political prisoners and 40,000 died as slave labourers.

Hitler Appoints Twelve Field Marshals

On 19. July, at a ceremony at the Kroll Opera House, Hitler promoted nine generals from the Army and three from the Luftwaffe to the rank of Field Marshal:

• Walther von Brauchitsch, Commander in chief of the Army
• Wilhelm Keitel, Chief of Staff of the OKW
• Gerd von Rundstedt, Commander in chief of Army Group A
• Fedor von Bock, Commander in chief of Army Group B
• Wilhelm von Leeb, Commander in chief of Army Group C
• Günther von Kluge, Commander of the Fourth Army
• Wilhelm List, Commander of the Twelfth Army
• Erwin von Witzleben, Commander of the First Army
• Walter von Reichenau, Commander of the Sixth Army
• Albert Kesselring, Commander of the Second Air Fleet
• Erhard Milch, Inspector General of the Luftwaffe
• Hugo Sperrle, Commander of the Third Air Fleet

This number of promotions to what had previously been the highest rank in the Wehrmacht (Hermann Göring, Commander in chief of the Luftwaffe and already a Field Marshal, was elevated to the new rank of Reichsmarschall) was unprecedented. Throughout the whole of the First World War, Kaiser Wilhelm II had promoted only five generals to Field Marshal.

Casualties

Axis

German overall casualties are hard to determine. A common estimate is about 27,074 killed, 111,034 wounded and 18,384 missing. Nevertheless, Germans killed may have been as high as 49,000 men, due to additional non-combat causes, wounded who died and missing who were confirmed dead.

The battle for France had cost the Luftwaffe 28% of its front line strength, some 1,236—1,428 aircraft destroyed (1,129 to enemy action, 299 in accidents). A further 323—488 were damaged (225 to enemy action, 263 in accidents), making a total of 36% of the Luftwaffe strength negatively affected. Luftwaffe casualties amounted to 6,653, including 4,417 aircrew; of these 1,129 were killed and 1,930 missing and captured. A great number were liberated from French prison camps upon the French capitulation.

Italian casualties were 1,247 killed or missing and 2,361 wounded. Additionally, there were more than 2,000 cases of frostbite from combat in the subzero temperatures of the French Alps.

Allied

Casualties were as follows:

France: According to the Defence Historical Service, 85,310 killed (including 5,400 Maghrebis), 12,000 missing, 120,000 wounded and 1,540,000 captured (including 67,400 Maghrebis). Some recent French research indicates that the number of killed had been between 55,000 and 85,000. In August 1940, 1,540,000 prisoners were taken into Germany where roughly 940,000 remained until 1945 when they were liberated by advancing Allied forces. At least 3,000 Senegalese Tirailleurs were murdered after being taken prisoner. While in German captivity, 24,600 French prisoners died; 71,000 escaped; 220,000 were released by various agreements between the Vichy government and Germany; several hundred thousand were paroled because of disability and/or sickness. Aerial losses are estimated at 1,274 aircraft destroyed during the campaign.

Britain: 68,111 killed in action, wounded or captured. Some 64,000 vehicles destroyed or abandoned and 2,472 guns destroyed or abandoned. RAF losses throughout the entire campaign (10 May – 22 June) amounted to 931 aircraft and 1,526 casualties.

Belgium: Losses in manpower were 6,093 killed and wounded. Some 2,000 prisoners of war died in captivity and more than 500 were missing. Those captured amounted to 200,000. Belgian wounded amounted to 15,850. They lost 112 aircraft destroyed.

Poland: Losses in manpower were around 6,000 killed and wounded. Nearly 12,000 troops (2d Infantry Division) were interned in Switzerland for the duration of the war.