First part of “Dunkirk” series:

Prelude

British troops in the sand dunes at Dunkirk, 1940. Without telling the French, the British began planning on 20 May for Operation Dynamo, the evacuation of the British Expeditionary Forces, as the German troops advanced into further mainland territory. Ships began gathering at Dover for the evacuation. On 20 May, the British Army started to evacuate unnecessary personnel. Then was when the shortage of food and water was noticed, with chaos starting to run among the soldiers. Two days later, BEF was ordered to attack southward to reconnect with the remainder of the French forces. This operation was impossible to carry out and the British and French forces withdrew to Dunkirk as fast as they could. By 24 May, the Germans had captured the port of Boulogne and surrounded Calais. Two days later, Hitler ordered the panzer groups to continue their advance, although most units took another 16 hours to attack, giving the Allies time to prepare defences and prevent the Germans from stopping the retreat.