The invasion of France was code-named ‘Case Yellow’. The plan had been devised by von Manstein, but had been credited to Hitler. It was a variation of the Schlieffen Plan from the First
World War. The Schlieffen plan had the objective of drawing the allies into the Low Countries. They would follow this by swinging through behind the allies and ending up in Paris, thereby encircling the allied forces. The plan had just failed in the First World War, but the Germans were confident that it would bring them victory this time. However, the plans for Operation Yellow had fallen into the hands of the allies through an unfortunate accident. This meant that the German staff had to rethink their plan of attack. This time von Manstein envisaged a spoiling attack in the Low Countries, like the original plan. The main change was the direction of the main thrust. It would be delivered through the Ardennes region which was thought to be tank-proof. For the attack the Germans split their forces into three Army Groups. Army Group B would advance through Holland and Belgium, thereby providing the bait for the allies. Army Group A would move through the Ardennes and would provide the main thrust. Army Group C would be opposite the Maginot Line and would keep the French defenders busy. The main thrust had the objective of racing through the enemy positions and on towards the French coast near Bolougne and Calais.
The allies anticipated a re-run of the First World War plan and they distributed their forces accordingly. The bulk of them were positioned north in readiness for the expected attack through the Low Countries. They had two further lines of reserves: one of these was positioned in the Ardennes region. The allies grossly overestimated the tank strength of the Germans and thought that they had over seven thousand tanks.
The reality was that, although the Panzerwaffe had now been expanded to ten Panzer Divisions, the Germans had just over 2,400 tanks for the attack. In the form of the Panzer I, over 1,400 of these were no more than armoured machine gun carriers. The allies had over 3,300 tanks to field against the Germans. In the important areas of main gun and armour protection, the allied machines outclassed the German tanks.
A German tank crew perch on the hulk of a knocked out French tank during the early phases of the French campaign.
When the attack began in the early hours of 10th May it caught the allies by surprise. The Germans made quick gains and good advances. This was helped considerably as the allied strength was in the north, whereas the bulk of the German strength would smash through the Ardennes, further south. The allied thinking had lulled them into a false sense of security and they felt confident that they would destroy the Germans easily. Although the Germans lacked numerical superiority in machines, they had been training hard on their new concepts and had tested the co-ordination of their forces. The concept was fairly simple, but very effective and advanced for the time.
A point of impact would be chosen that was small in width. The armour would concentrate on this central point and the weight of firepower would be used to overwhelm the enemy. Once a breech had been made the rest of the Division would rush through the gap and into the rear enemy areas. The tanks would continue to race deep inside the enemy lines, whilst the infantry and artillery would deal with any pockets of resistance and capture key objectives. The anti-tank gunners would set up a defensive screen to protect the areas already captured. Under this well coordinated attack, the allies fell back in confusion and panic. They were still thinking of the last war and were prepared for a defensive battle. The Germans had proved that a rapid deep advance into the enemy lines provided its own defence.
The strategy that had eventually been settled upon for the attack was of breath taking audacity.
A surprise offensive was launched through Holland and Belgium which it was hoped would draw the allied forces northwards away from their entrenched defensive positions in France. Then a powerful concentration of German armour would crash through the weakly defended Ardennes region. Without real opposition, this arm of the attack would thrust into France to tear the allied armies in half.