On the 10th May 1940, German army group B invaded Holland, Luxembourg and Belgium. In response, three allied armies were committed to the river Dyle to counter-attack. At the same time, German army group A burst through the Ardennes and advanced very quickly towards the French coast and the English Channel.
By taking Boulogne sur Mer and Calais, the Germans succeeded in surrounding the allied troops in the so-called « sickle cut ».
Holland capitulated on the 15th May, and Belgium on the 28th. Facing an enemy which was better equipped and which outnumbered the allied troops, retreat was the only option for the French armies and the British Expeditionary Force, that had been stationed on the continent since the beginning of the “Phoney War” in September 1939.
15,000 French and British troops defended a narrow perimeter to prevent the Germans from taking Dunkirk. Thanks to the sacrifices of these soldiers, a ragtag fleet of around 1400 mainly British, but also French, Belgian and Dutch ships, succeeded in rescuing more than 338,000 soldiers from the beaches and the eastern mole.
On the 4th June, at dawn, the last ship left Dunkirk and the Germans entered the city that was in ruins. The success of the biggest evacuation in military history, a « Disaster turned to Triumph », gave a great boost to British morale, and is now seen as a major turning point of World War II.