German Army Group A Breaks Defenses at Sedan

On the morning of 15 May German Army Group A broke the defences at Sedan and was now free to "dash" to the English Channel.

The Allies now considered a whole sale withdrawal from the Belgian trap. The withdrawal would reflect three stages: night of 16/17 May to the River Senne; night of 17/18 May to the river Dendre; night of 18/19 May to the river Scheldt. The Belgians were reluctant to abandon Brussels and Leuven, especially as the Dyle line had withstood German pressure well. The Belgian Army, B.E.F and French First Army, in a domino effect, was ordered/forced to retire on 16 May to avoid their southern flanks from being turned by the German armour forces advancing through the French Ardennes and the German Sixth Army advancing through Gembloux. The Belgian Army was, along with the French Seventh and British Army, holding the German Fourteenth Army on the K.W line. Had it not been for the collapse of the French Second Army at Sedan, the Belgians were confident they could have held the line, and checked the German advance.

Churchill flew to Belgium on May 16. General Gamelin, shocking Churchill with the hemorrhage of the front at Sedan, listed defeat after defeat as the weight of five German divisions bared down on Paris. “Where is the strategic reserve?” asked Churchill. “There is none.” Replied Gamelin. Churchill returned to London with the first of two great shocks of the war, the other was the loss of the HMS Prince of Wales in December 1941.