Dunkirk Evacuation
The Dunkirk Evacuation, also known as Operation Dynamo was an operation during World War II to rescue the Allied Expeditionary Force following its encirclement by German forces. Having bungled the start of the war by sending their best mobile units north where they were then cut off by the German drive to the sea, the Allies lacked a mobile reserve to punch through to allow them to retreat into France. Instead, they fell back on the French port of Dunkirk, near the Belgian border. Under relentless German air attack, the British and French held the perimeter long enough for the Royal Navy and civilian boats to extract the majority of the force, numbering several hundred thousand, albeit without most of their heavy equipment.
The force was reequipped and formed the nucleus of the new British and Free French armies that went on to retake North Africa, Italy, France, and invade Germany.