Operation Dynamo, the evacuation of Dunkirk, began nearly 80 years ago today.

In May of 1940, British, French, and Belgian troops were trapped by the German army in western France. Blitzkrieg, or “lightning war” had proven terribly effective.

With the Allied armies nearing total collapse as the Germans neared the French coastline, the British launched at Dunkirk the largest evacuation and rescue mission that the world had ever seen.

WWII began in September 1939 when the Nazis invaded Poland. The British and French declared war on Germany and Britain sent the British Expeditionary Force (BEF) to the French border with Germany to sit all winter waiting for the inevitable invasion.