As part of the Nazi-Soviet Non-Aggression Pact in August of 1939, Germany conceded that the Soviets would gain parts of Poland and the Baltic States. For the Nazi, it prevented a two-front war – one in the west as German forces advanced towards France and against the Soviet Union, whom Hitler despised. Both Stalin and Hitler knew the pact would not last.
When the Battle of France began on May 11th, 1940, the German armor units surprisingly broke through the Ardennes region and advanced north. At the same time the Germans advanced in the east, controlling the Netherlands and into Belgium. This divided the combined forces of the British, French, and Belgian and the advance of the powerful Panzer divisions trapped Allied soldiers along the French-Belgium border.
The British, seeing that the effort to save France was lost, planning of an operation to evacuate was made, so troops could return to England for its defense.
On May 28th, a huge operation attempted rescue in which 16,000 men were put on board ships but nine destroyers (needed to fight against U-boats in the area) and many other vessels were either badly damaged or sunk. RAF pilots flew to the area to fight against the Lutwaffe who was strafing and bombing Dunkirk, its harbor and troops and equipment on the beaches as well as rescue vessels. In one day the RAF lost 177 planes and the Lutwaffe lost 132.
The British Expeditionary Force was led by Lord Gort. The German advance was commanded by General von Brock and General von Rundstedt with an armored group commanded by General von Kleist. General von Kleist was one of the officers that plotted against Hitler and survived, dying at the age of 90.
The major success of the Dunkirk evacuation was that the German high command and Hitler decided to stop its advance upon Dunkirk, which is still argued today by historians as to what reasoning was behind one of the major blunders of the Nazi in WWII. The result, however, was in favor of the Allies where 30,000 troops were evacuated the first day, 68,000 troops evacuated on the second day, and 65,000 rescued on June 1st, 1940. The operation lasted until June 4th and five nations took part: Britain, France, Belgium, Netherlands, and Poland. The total amount of troops evacuated was 338,226 troops, taken to Dover by 900 vessels of various sizes – civilian and military. An eyewitness, Arthur D. Divine described the scene:
It was the queerest, most nondescript flotilla that ever was, and it was manned by every kind of Englishman, never more than two men, often only one, to each small boat. There were bankers and dentists, taxi drivers and yachtsmen, longshoremen, boys, engineers, fishermen and civil servants. . .
It was not only a physical victory, but a demonstration of the Britons determination; despite Winston Churchill's warning:
We must be careful not to assign to this deliverance the attributes of a victory. Wars are not won by evacuations.
On the day the evacuation started, German artillery setup position and provided a constant heavy artillery bombardment, despite the order for the armor to stop after defeating Allied defenses at Calais. Defenses at Dunkirk included flooding the canals and large areas of low ground, providing an anti-tank defense position. Before the evacuation, Belgium signed an unconditional surrender and the hopes of the French commander to stop the Germans was lost. That element decided to remain and not evacuate in hopes of winning against the Germans. Despite that lost hope, the French First Army reached Dunkirk, four British divisions escaped the German pincer trap, but the French V Corps was captured.
When the evacuating naval vessels got back to Dover with the troops, more problems developed. The port of Dover had eight berths for ferries crossing the channel and only three ships could berth at one time. Once the troops disembarked ships the men moved to a staging area away from the dock where they were provided shelter and food. Admiral Ramsey had planned to be evacuating 45,000 troops over a two-day period; but that amount would be increased at least three fold.
The British lost all heavy equipment that included tanks and artillery, left behind at Dunkirk beaches. The British Expeditionary Force lost 68,111 troops were were killed, wounded or taken prisoner. Equipment lost: 2472 guns, 63,879 vehicles, 20548 motorcycles and 500,000 tons of supplies and ammunition. The actual number of prisoners captured has never been determined, but Nazi records shows the amount to be 80,000 captured at Dunkirk alone. Approximately 243 ships were sunk, civilian and naval, which included six (or 9 depending on source) Royal Navy destroyers and 19 took damage.
Following the Dunkirk battle and evacuation, Winston Churchill delivered one of his most famous speeches:
Even thought large tracts of Europe and many old and famous States have fallen or may fall into the grip of the Gestapo and all the odious apparatus of Nazi rule, we shall not flag or fail. We shall go on to the end. We shall fight in France, we shall fight in the seas and oceans, we shall fight with growing confidence and growing strength in the air; we shall defend our Island, whatever the cost may be. We shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender; and even if, which I do not for a moment believe, this Island or a large part of it were subjugated and starving, then our Empire beyond the seas, armed and guarded by the British Fleet, would carry on the struggle, until, in God's good time, the New World, with all its power and might, steps forth to the rescue and the liberation of the Old.
Dunkirk 1940: Operation Dynamo; Douglas C. Dildy.