The British Commandos were a formation of the British Armed Forces organized for special service in June 1940. After the events leading to the British Expeditionary Force's (BEF) evacuation from Dunkirk, after the disastrous Battle of France, Winston Churchill, the British Prime Minister, called for a force to be assembled and equipped to inflict casualties on the Germans and bolster British morale. Churchill told the joint chiefs of staff to propose measures for an offensive against German-occupied Europe, and stated in a minute to General Ismay on 6 June 1940: "Enterprises must be prepared, with specially-trained troops of the hunter class, who can develop a reign of terror down these coasts, first of all on the "butcher and bolt" policy..." The Chief of the Imperial General Staff at that time was General Sir John Dill and his Military Assistant was Lieutenant Colonel Dudley Clarke. Clarke discussed the matter with Dill at the War Office and prepared a paper for him that proposed the formation of a new force based on the tactics of Boer commandos, 'hit sharp and quick - then run to fight another day'; they became 'The Commandos' from then onwards. Dill, aware of Churchill's intentions, approved Clarke's proposal. The first commando raid, Operation Collar, was conducted on the night of 24/25 June 1940.