This is the Naval Staff History of "Operation Dynamo", originally published internally in 1949. British ships evacuated nearly 100,000 men of the BEF from the beaches, and over 200,000 from harbours. Other nations' vessels carried more than 30,000. Scores of ships were lost during the operation, and many more were seriously damaged, but a very large proportion of the British Army had been rescued in the teeth of continual air attack, from an every-shrinking perimeter. The troops then had to be transported across the Channel in the face of enemy aircraft, mines, torpedoes, and fire from the shore, through waters unlit and strewn with wrecks. Although the campaign was, in Churchill's words, "an unmitigated defeat", there is much to take pride in, and many lessons to be learned from this operation. The appedices include a list of ships which took part in "Operation Dynamo", and numbers of troops transported.