26 May - 4 June 1940

Second World War

Operation Dynamo, the evacuation from Dunkirk, involved the rescue of more than 338,000 British and French soldiers from the French port of Dunkirk between 26 May and 4 June 1940. The evacuation, sometimes referred to as the Miracle of Dunkirk, was a big boost for British morale. Prime Minister Winston Churchill recognised however that the greatest challenge still lay ahead, as Nazi ambitions now turned toward Britain. 


6 Facts About the Dunkirk Evacuation

Discover more about the Dunkirk evacuation and a few highlights from our collection. 


1. It was a rescue mission

On 10 May 1940, Germany invaded France and the Low Countries, pushing the British Expeditionary Force (BEF), along with French and Belgian troops, back to the French port of Dunkirk. A huge rescue, Operation 'Dynamo', was organised by the Royal Navy to get the troops off the beaches and back to Britain.


2. The evacuation was code-named Operation Dynamo

Admiral Bertram Ramsay directed the evacuation. Ramsay had retired before the war but was recalled in 1939. He and his staff worked in a room deep in the Dover cliffs that had once contained a dynamo, a type of electrical generator, giving the operation its name.


3. The Evacuation Began on 26 May

'Dynamo' began on 26 May. Strong defences were established around Dunkirk, and the Royal Air Force sent all available aircraft to protect the evacuation. Over 800 naval vessels of all shapes and sizes helped to transport troops across the English Channel. The last British troops were evacuated on 3 June, with French forces covering their escape.


4. The- 'Little Ships' helped

The gently shelving beaches meant that large warships could only pick up soldiers from the town's East Mole, a sea wall which extended into deep water, or send their boats on the beaches to collect them. To speed up the process, the British Admiralty appealed to the owners of small boats for help. These became known as the 'little ships'.


5. Over 300,000 soldiers were rescued

Evacuated troops on a destroyer about to berth at Dover, 31 May 1940.
© IWM (H 1637)

Churchill and his advisers had expected that it would be possible to rescue only 20,000 to 30,000 men, but in all 338,000 troops were rescued from Dunkirk, a third of them French. Ninety thousand remained to be taken prisoner and the BEF left behind the bulk of its tanks and heavy guns. All resistance in Dunkirk ended at 9.30am on 4 June.


6. The evacuation boosted morale

The Dunkirk evacuation was an important event for the Allies. If the BEF had been captured, it would have meant the loss of Britain's only trained troops and the collapse of the Allied cause. The successful evacuation was a great boost to civilian morale, and created the 'Dunkirk spirit' which helped Britain to fight on in the summer of 1940.

Operation Dynamo explained

Operation Dynamo is often described as a miracle. Over 338,000 allied soldiers were rescued from Dunkirk in the face of overwhelming odds.

Discover what made the evacuations from Dunkirk so successful, how the British evacuation was carried out and why Winston Churchill regarded the operation as a 'miracle of deliverance'.

The British evacuation from Dunkirk is often described as a miracle. Over 300,000 Allied soldiers pulled from the sea in the face of overwhelming odds and the so-called 'Dunkirk spirit' that made it happen helping Britain through its darkest hour. But what made the evacuations from Dunkirk so successful? and are the myths surrounding the operation to be believed?

Well before we answer those questions and more a reminder to subscribe to the Imperial War Museums YouTube channel for more videos just like this every two weeks.

The Dunkirk evacuation is looked upon as a miracle, a miracle of deliverance I think Churchill himself called it in the House of Commons. But it's not so much a miracle as a coming together of series of circumstances which played into the hands of Britain.

And to be fair to the Allies they hadn't had much luck so far. Two weeks previously Germany began its invasion of the Low Countries with French and British forces then moving into Belgium to meet them, however this attack was just a diversion. Using cutting-edge blitzkrieg tactics German tanks smashed through the Allied weak point in the Ardennes and dashed to the coast surrounding the allies. If you want to find out what made this blitzkrieg attack so powerful we've got a video all about that linked in the description below.

In Belgium and part of Northern France, we have virtually the whole of the British expeditionary force and a French army surrounded with their backs to the coast. So the British army started thinking about evacuation before anybody else did because they thought they might be able to save some of their army from what looked like a terrible disaster.

But time was against them, the German spearhead that had cut the Allies off then began taking channel ports despite desperate Allied attempts to hold on to them. By May 26th Dunkirk was the final port remaining. Worse still the port itself had been badly damaged, leading to dire predictions of what would actually be possible during the evacuation.

Well, the initial thoughts of the British government and high command was that they were going to try to save what they could. There was no expectation of getting the whole British Expeditionary Force out they thought they might get act between 30 and 45,000 men.

Despite those predictions though the evacuation, codenamed Operation Dynamo, eventually managed to save over 338,000 Allied soldiers. So how did they do it? Well according to Paul there are three things that made these evacuations so successful. First was the weather.

Yeah, the weather could hardly have been more favourable. There were very unusually for that time of year very light winds for most days there was not a lot of surf on the beach.

That allowed men to load into smaller boats right on the beaches before boarding for larger ships, an impossible task on windier days, and when there was wind, that played into the Allies hands as well.

The wind was from the east which blew smoke from the burning port of Dunkirk across the beach offering a bit of cover from air attack and also there's some low cloud for most of the period of the evacuation. Low cloud over the beach also protected the troops from air attack so they won in every sense weather-wise.

Next up was a bit of ingenuity from the naval officer in charge of the evacuation, Captain William Tennant, which goes against one of those classic Dunkirk narratives.

One of the things we remember or think we remember about Dunkirk is the little boats who took men off the beaches. Certainly they were there, over 300 of them, but that was a minority of the men who escaped. Most of the evacuation took place across one of the harbour breakwaters at Dunkirk. This was a very narrow thing with a walkway on top of it. Most of the men, I think around 200,000 of the 338,000 men, came off through that route as opposed to the beaches.

The harbour mole was so effective because it allowed troops to step right from the harbour onto destroyers or other large ships rather than going through the time-consuming process of taking smaller boats from the beach. The mole was never designed to be used this way, but it was a major factor in making the Dunkirk evacuations such a success.

Finally, let's look at the infamous German halt order which gave the Allies valuable time to create a defensive perimeter around the port of Dunkirk.

People in the higher German command basically could not believe their luck. They always were assuming that the French would manage to launch a counter-attack and cut off those tanks that were advancing with such speed. They kept trying to get tanks to slow down so the infantry could catch up and so this halt order on the 24th of May is sort of another iteration of that caution.

Another key issue were further Allied garrisons at other important towns. British defenders at Calais held on against all the odds until May 26th while French forces in Lille managed to occupy 10 German divisions alone.

The Germans realised that, even though they won this battle effectively, they had not defeated France. France still had a huge army and they were going to need all their tanks in order to achieve this after they dealt with whatever happened at Dunkirk. They also thought that the German air force could destroy the troops in the bridgehead or any ships trying to save them, this was why that order was issued.

Bring all of this together and you can see why so many more troops were saved than expected. The weather providing valuable cover from air attack, the harbour mole allowing extra men to embark, and the German halt order giving the Allies valuable time to set up defences.

But what was it actually like to be in the town of Dunkirk?

The soldiers there had a variety of experience and the British Army behaved in a variety of different ways. There was some heroism, on the other hand, there were instances of disorder and instances of panic.

Scenes on the beaches varied from boredom as soldiers waited for pickup, to bedlam as the Luftwaffe swirled overhead. According to one soldier writing in his diary on May 30th, the situation was desperate "every man for himself getting loaded".

We have in our collection a small French railway map which was pinched from the wall of a cafe by a soldier Bill Osborne. He expected that he might get separated from his unit and have to find his own way to the coast things were that chaotic. He also wrote a letter on a scrap of paper to his wife anticipating that he would be killed and telling her to make a new life with somebody else if she could.

And for the soldiers who did escape the stress was not over. They were expecting a frosty reception on their return to Britain.

They thought that they would be vilified by the public. They thought that they'd arrived home with their tail between their legs and yet they found themselves treated largely as heroes uh because people were so relieved at having saved so many men and this, for obvious reasons of national morale, was the line pushed by the press and the BBC. It was extraordinary that they'd saved as many men as they had, well what it didn't point out was that we'd had to leave all our equipment behind and Britain was effectively open to invasion at that point had the germans had either the plans or the will or the ability to do it.

And that's the reason that so many of these myths surrounding Dunkirk exist. British morale was at a low point and so the British press emphasized stories of heroism like those so-called little ships. Most of those craft were piloted by Royal Navy crews rather than civilians and yet these stories of plucky Brits winning against the odds are the stories which have stuck around, part of what's become known as the 'Dunkirk spirit'.

The myth certainly was necessary at the time you know keep people's morale up. Although Churchill in the House of Commons was was fairly straight with the House of Commons and said you know this is a deliverance but "wars are not won by evacuations". Victory for Britain was a long way off, but the evacuation at Dunkirk was one of the few rays of light in the Allied cause. It was a great success coming at the end of a dismal failure, a success which kept the British army intact and British morale afloat, for now. The following month France surrendered to Germany. The battle of Britain was about to begin.

Explore Our Collection

You can find photos, film and objects related to the Dunkirk evacuations on Collections Online.

Souvenirs and ephemera

musical instrument, accordion



Souvenirs and ephemera




Vehicles, aircraft and ships

Ship, Fishing Boat 'Tamzine', British



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