Air Chief Marshal Sir Geoffrey Salmond and his brother Jack joined the Royal Flying Corps during the Great War. Both were to have a major influence on the development of the RAF in the 1920s and 1930s, in particular Geoffrey who became one of the original pioneers of high speed flight. Extraordinarily, both brothers rose to become Chiefs of the Air Staff in the 1930s. Without Sir Geoffrey Salmond's vision the RAF would almost certainly not had the Spitfire and the result of the Battle of Britain would surely have been very different.