World War II: Battle and Evacuation of Dunkirk

British forces leaving Dunkirk
British troops evacuating Dunkirk, May 1940. Photograph Courtesy of the US Department of Defense

Conflict:

The Battle and evacuation of Dunkirk occurred during World War II.

Dates:

Lord Gort made the decision to evacuate on May 25, 1940, and the last troops departed France on June 4.

Armies & Commanders:

Allies

  • General Lord Gort
  • General Maxime Weygand
  • approx. 400,000 men

Nazi Germany

Background:

In the years prior to World War II, the French government invested heavily in series of fortifications along the German border known as the Maginot Line.

It was thought that this would force any future German aggression north into Belgium where it could be defeated by the French Army while sparing French territory from the ravages of war. Between the end of the Maginot Line and where the French high command expected to meet the enemy lay the thick forest of the Ardennes.  Due to the difficulties of the terrain, French commanders in the early days of World War II did not believe that the Germans could move in force through the Ardennes and as a result it was only lightly defended. As the Germans refined their plans for invading France, General Erich von Manstein successfully advocated for an armored thrust through the Ardennes. This attack he argued would take the enemy by surprise and allow for a rapid movement to the coast which would isolate Allied forces in Belgium and Flanders.

On the night of May 9/10, 1940, German forces attacked into the Low Countries.

Moving to their aid, French troops and the British Expeditionary Force (BEF) were unable to prevent their fall. On May 14, German panzers tore through the Ardennes and began driving to the English Channel. Despite their best efforts, the BEF, Belgian, and French forces were unable to halt the German advance.

This occurred even though the French Army had fully committed its strategic reserves to the fight. Six days later, German forces reached the coast, effectively cutting off the BEF as well as a large number of Allied troops. Turning north, German forces sought to capture the Channel ports before the Allies could evacuate. With the Germans at the coast, Prime Minister Winston Churchill and Vice Admiral Bertram Ramsay met at Dover Castle to begin planning the evacuation of the BEF from the Continent.

Traveling to Army Group A's headquarters at Charleville on May 24, Hitler urged its commander, General Gerd von Rundstedt, to press the attack. Assessing the situation, von Rundstedt advocated holding his armor west and south of Dunkirk, as the marshy terrain was unsuitable for armored operations and many units were worn down from advance west. Instead, von Rundstedt suggested using the infantry of Army Group B to finish off the BEF. This approach was agreed upon and it was decided that Army Group B would attack with strong aerial support from the Luftwaffe. This pause on the part of the Germans gave the Allies valuable time to construct defenses around the remaining Channel ports. The following day, the commander of the BEF, General Lord Gort, with the situation continuing to deteriorate, made the decision to evacuate from northern France.

Planning the Evacuation:

Withdrawing, the BEF, with support from French and Belgian troops, established a perimeter around the port of Dunkirk. This location was chosen as the town was surrounded by marshes and possessed large sand beaches on which troops could gather prior to departure. Designated Operation Dynamo, the evacuation was to be carried out by a fleet of destroyers and merchant ships. Supplementing these ships, were over 700 "little ships" which largely consisted of fishing boats, pleasure craft, and smaller commercial vessels. To execute the evacuation, Ramsay and his staff marked out three routes for vessels to use to between Dunkirk and Dover.  The shortest of these, Route Z, was 39 miles and was open to fire from German batteries. 

In planning, it was hoped that 45,000 men could be rescued over two days, as it was expected that German interference would force the end of the operation after forty-eight hours.

As the fleet began to arrive at Dunkirk, the soldiers commenced preparing for the voyage. Due to time and space concerns, almost all heavy equipment had to be abandoned.  As German air attacks worsened, the town's harbor facilities were destroyed.  As a result, departing troops boarded ships directly from the harbor's moles (breakwaters) while others were forced to wade out to waiting boats off the beach. Commencing on May 27, Operation Dynamo rescued 7,669 men on the first day and 17,804 on the second.

Escape Across the Channel:

The operation continued as the perimeter around the port began to shrink and as the Supermarine Spitfires and Hawker Hurricanes of Air Vice Marshal Keith Park's No. 11 Group from the Royal Air Forces' Fighter Command battled to keep German aircraft away from the embarkation areas. Hitting its stride, the evacuation effort began to peak as 47,310 men were rescued on May 29, followed by 120,927 over the next two days. This occurred despite a heavy Luftwaffe attack on the evening of the 29th and the reduction of the Dunkirk pocket to a five kilometer strip on the 31st.  By this time, all BEF forces were within the defensive perimeter as was over half of the French First Army. Among those to leave on May 31 was Lord Gort who gave command of the the British rearguard to Major General Harold Alexander.

On June 1, 64,229 were taken off, with the British rearguard departing the next day. With German air attacks intensifying, daylight operations were ended and the evacuation ships were limited to running at night. Between June 3 and 4, an additional 52,921 Allied troops were rescued from the beaches. With the Germans only three miles from the harbor, the final Allied ship, the destroyer HMS Shikari, departed at 3:40 AM on June 4. The two French divisions left defending the perimeter were ultimately forced to surrender.

Aftermath:

All told, 332,226 men were rescued from Dunkirk. Deemed a stunning success, Churchill cautiously advised “We must be very careful not to assign to this deliverance the attributes of a victory.

Wars are not won by evacuations." During the operation, the British losses included 68,111 killed, wounded, and captured, as well as 243 ships (including 6 destroyers), 106 aircraft, 2,472 field guns, 63,879 vehicles, and 500,000 tons of supplies. Despite the heavy losses, the evacuation preserved the core of the British Army and made it available for the immediate defense of Britain. In addition, significant numbers of French, Dutch, Belgian, and Polish troops were rescued.

Selected Sources