May 10 1940, the Germans launch Case Yellow (Fall Gelb) and within around 2 weeks the core of the French Army is eliminated, the British are driven from the continent, Belgium and the Netherlands surrender. The German victory creates a ton of myths that linger on. 1/

Some created by the Germans some created by the defeated to justify the collapse. It isn’t far off saying that, other than the outlines, most of what people think about the campaign isn’t accurate. The campaign isn’t a triumph of German Panzers and Stukas 2/

Over French forces fighting the last war and certainly not over cowardly French forces - which remains the most pernicious myth from the campaign. The myth of cowards was a self-serving story created the defeated French generals in Vichy to justify their own awful performance. 3/

The German victory is improbable and the result of a strategic design that pierced the French center with a massive concentration of tanks and then conducts a massive envelopment of the Anglo-French armies in Belgium. 4/

The plan is innovative but not widely liked within the German officer corps. The bulk of the officers do not trust the concentration of the Panzers & are wary of another risky “all or nothing” strike at the French. This opposition is shown in the organization of the attack 5/

Panzergruppe Kleist leads the offensive as opposed to a “Panzerarmee”. The German generals do not want to recognize the concentration of Panzer divisions as anything permanent. PG Kleist is a short term expediency to most that will be dissolved once the infantry catches up. 6/

It is one reason the believers like Guderian press forward so aggressively. They are fighting for their organizational lives & professional vision against an officer corps who do not share their vision and if they falter they will be re-integrated into the foot army. 7/

This is far from the vision of the innovative German Army most people believe in. Throughout the campaign it is the functional insubordination of Corps/ Divisional commanders working against the designs of their own high command that create many of the most dramatic victories. 8/

The French plan is designed to hold along the Maginot and behind the Ardennes while pushing the French Army and BEF to Belgium to link with the Belgian forces along the Dyle River and is known as the Dyle Plan. This plan was designed to fight in Belgium not in France. 9/

Fighting outside France was an obsession for French leadership because so much of their natural resources, manpower, & industrial capability were so close to the German border. France is aware of their weaknesses in industrial capability & manpower vs the Germans 10/

The Dyle Plan received a disasterous modification in March 40 when Marshal Gamelin adds a Breda Variant. This modification has the French pushing all the way to Breda to link with the Dutch army and deny Germans access to the Schledt. In order to do this he removes 7th Army 11/

From the general reserve & moves it to the Channel to push past Antwerp to Breda. The location of 7 Army & planned movement is shown in Blue, the German attack in Red & where 7 Army should have been before the Breda variant is the Green marker. The well equipped and mobile

7 Army at Reims as planned would have been a huge threat to the German advance. The first stage of the German advance is through Luxembourg & the Belgian Ardennes. This road network is poor & the Germans spend massive planning effort to move 40k+ vehicles through this area. 13/

Kleist even threatens to execute MPs who do not enforce the march plan. The Germans expect to fight 2 lines of Belgian defenses in the forest. The French expect the Belgians to delay the Germans while French light forces move into delaying positions in the Ardennes . 14/

The Belgians however do not plan to fight in the Ardennes at all. They plan to create obstacles & withdraw to the northwest. Disastrously their withdraw plan is a swinging door that opens the way to the French border & worse the obstacles they deploy delay the French advance 15/

The one place the Belgians do fight shows the potential to delay the Germans in this terrain. At Bodange on May 10, 2 companies of light Belgian infantry delay the advance of Guderian’s entire Panzer Corps for about 6 hours because they do not get the withdrawal order. 16/

Ironically, this is because the Germans cut their phones lines or else they too would have fallen back without a shot. Despite the general Belgian withdrawl, isolated resistance and the terrain leaves the Germans short of their day 1 objectives on May 10. 17/

The Allies begin moving forward in line with the Dyle Plan. most allied air assets are deployed in Belgium. As part of the deception,Luftwaffe activity on May 10 is also concentrated over Belgium to convince the Allies this is the primary effort. Allied Aerial reconnaissance 18/

over the Ardennes is limited. There are scattered reports of large German formations moving in the area but the French command is focused on the Belgian plain. Plus, any German movement through the Ardennes is expected to take weeks to to reach the Meuse. 19/