Marshal of the Royal Air Force Sir John Cotesworth Slessor, was a senior commander in the Royal Air Force (RAF), serving as Chief of the Air Staff from 1950 to 1952. As a pilot in the Royal Flying Corps during the First World War, he saw action with No. 17 Squadron in the Middle East, earning the Military Cross, and with No. 5 Squadron on the Western Front, where he was awarded the Belgian Croix de Guerre. Between the wars he commanded No. 4 Squadron in England, and No. 3 (Indian) Wing, earning the Distinguished Service Order for operations with the latter in Waziristan. In 1936, he published Air Power and Armies, which examined the use of air power against targets on and behind the battlefield.

Marshal of the Royal Air Force (MRAF) is the highest rank in the Royal Air Force (RAF). In peacetime it was granted to RAF officers in the appointment of Chief of the Defence Staff (CDS), and to retired Chiefs of the Air Staff (CAS), who were promoted to it on their last day of service. While surviving Marshals of the RAF retain the rank for life, the highest rank to which officers on active service are promoted is now air chief marshal. Although general promotions to Marshal of the Royal Air Force have been discontinued since the British defence cuts of the 1990s, further promotions to the rank may still be made in wartime, for members of the Royal Family and certain very senior RAF air officers in peacetime at the discretion of the monarch; all such promotions in peacetime are only honorary, however. In 2012, the then Prince of Wales was promoted to the rank in recognition of his support for his mother, Queen Elizabeth II, in her capacity as head of the armed forces (commander-in-chief), while in 2014 Lord Stirrup, who had served as Chief of the Air Staff and Chief of the Defence Staff for over seven years, was also promoted.