Formed in Plymouth in late June 1940 following the Dunkirk evacuation, under the command of Lieutenant Colonel John Durnford-Slater, No. 3 Commando was the first British unit to use the title of "Commando". By 5 July 1940 they had been fully raised and a little more than a week later they carried out one of the first Commando raids of the war. This raid, known as Operation Ambassador, which had been hastily organised at the behest of the British prime minister, Winston Churchill, was probing raid on the German-occupied island of Guernsey. As a result of a number of mishaps and hurried planning, the raid proved to be unsuccessful.