On this day in 1940, the Battle of Dunkirk ends with a German victory and with Allied forces in full retreat.
Before the invasion of France, the Germans had tricked the French and British into thinking that they’d enter France through Belgium between the North Sea and the Ardennes Forest north of the Sambre and Meuse, but in actuality their main thrust came through the Ardennes itself. When the German forces under Field Marshal Gerd von Runstedt emerged from the forest to cross the Meuse at Sedan, they were far in the Allied rear.
The French had decided to establish a defensive line running along the River Dyle, with a narrow space in between it and the River Sambre, which was anchored on the Belgian fortress of Namur and called the Dyle Line. Into the gap, the so-called Gembloux Gap, between the two rivers the Germans had thrown substantial forces, but had been completely defeated by the French. Nonetheless the sudden appearance of the German armoured forces so far in the French rear compelled the latter to beat a hasty retreat to the southwest to escape the German encirclement.
They were not successful. The Germans raced to the Somme and reached the Channel on the May 26. This trapped over thirty of the best French divisions and virtually the whole of the British Expeditionary Force in Belgium and northern France. French forces south of the Somme attempted to break through the German lines at Abbeville and Péronne, but were unable to do so.
Meanwhile the Germans tightened the noose on the trapped forces, who were behind an ever shrinking perimeter. As early as the May 25, British commander General Lord Gort requested permission to evacuate and began racing for the Channel at Dunkirk. On the 27th the British began withdrawing by ship. All sorts of ships were requisitioned for the operation, named Dynamo, including all types of civilian craft, as well as navy ships. An heroic effort was made by the sailors of England to rescue their soldiers from the jaws of defeat.
Curiously the Germans halted their forces while on the verge of victory. They could arguably have captured the whole of the BEF and had eliminated the only trained soldiers the UK possessed. The halt order originated at Army Group A and 4th Army headquarters the day before it was given (the halt order was given on May 24). Von Rundstedt, von Kluge, and von Kleist, faced with an amazing possibility of victory, simply lost their nerves. They did not think that the armored divisions would be able to hold their corridor to Dunkirk had they struck for it. The Battle of Arras had already made them nervous about this.
Hitler only got involved when von Brauchitsch took the 4th Army and gave it to von Bock so he could direct the encirclement. When Hitler found out, he was infuriated. He gave the army back to von Rundstedt, and quite clearly left the future course of operations to Army Group A. Hitler was convinced by von Rundstedt to stop for a bit. In any event, the fighting didn’t just end. The German infantry were still in motion fighting the Allies across the pocket’s perimeter.
In the subsequent Fuhrer Directive, Hitler demanded the annihilation of the trapped Allies.
It should be noted that the war wasn’t in its final stages in the Dunkirk battles. The Germans still needed their armor for Case Red. Von Rundstedt, a military conservative, had never been a huge fan of the Sedan breakthrough in the first place. Exposed flanks and lightning speed was simply too edgy for him. They also still had to defend against the south; the French below Army Group A were still there, they hadn’t disappeared.
The Battle of France was still an amazing victory for Germany, with or without the halt order.
But of course, after the war the German generals all blamed Hitler for the Miracle of Dunkirk in their memoirs. The fact of the matter is that it was a military decision. It wasn’t even evident to the Germans that the Allies had gotten a huge break at the time. When the halt order was rescinded, the Allies were still in a very desperate situation.
Many people have used the old cliché that Hitler ‘let’ the British escape in order to make peace with them. Apart from being militarily nonsensical, since destroying your enemy’s army would be the surest way to compel his surrender, it isn’t convincing.
Part of the reason seems to be that the French are so maligned and so easily dismissed in retrospect that people forget that they were still present. The French forces essentially sacrificed themselves so the British could escape, establishing a strong collapsing perimeter around Dunkirk until forced to surrender (after the British got off).
Secondly, the curious thing about the German drive is that the Germans were not aware of how successful they had been. They kept expecting to run into the ‘inevitable’ French counterattack, haunted as they were by the Marne. They still imagined the French had powerful reserves they were waiting to spring upon them, unaware that they had practically disembowelled the French Army.
Thirdly, Dunkirk is (or was in 1940) a shit harbour and can accommodate ships of no serious draught. When Dunkirk is called a miracle it is not just a euphemism, nobody in any military or political capacity of any country considered it possible. The British were literally lifted off the beach by (an improvised civilian fleet of) shallow-draught fishing trawlers and yachts, which responded remarkably to the crisis but which were entirely beyond the Admirality’s ability to control or direct.