The German military was one of the pioneers of the use of airborne formations, conducting several successful airborne operations during the Battle of France in 1940, including the Battle of Fort Eben-Emael. Impressed by the success of German airborne operations, the Allied governments decided to form their own airborne formations. This decision would eventually lead to the creation of two British airborne divisions, as well as a number of smaller units. The British airborne establishment began development on 22 June 1940, when the Prime Minister of the United Kingdom, Winston Churchill, directed the War Office in a memorandum to investigate the possibility of creating a corps of 5,000 parachute troops.