On 27 May 1940, British troops were forced to beat a humilating retreat from Dunkirk in France by advancing German forces.
Operation Dynamo, as the mission was called, managed to recover 338,000 men over the course of six days, largely in so-called 'little ships' - small, non-military vessels press-ganged into emergency service.
While the troops were saved, their equipment was not. Furthermore, German forces now controlled all of France, and Britain was left as the last of the countries standing against Hitler.
Watch original footage from the evacuations in this British Pathé video, above.