Francis Frederic "Frank" Inglis, was an officer in the Royal Air Force who became the head of RAF Intelligence Staff during the Second World War, reporting to Winston Churchill. In 1942 he was sent to America, where he successfully persuaded President Franklin D. Roosevelt to direct the main American war effort against Germany rather than Japan.
After graduating from Sandhurst, Inglis spent three years with the Duke of Cornwall's Light Infantry, reaching the rank of lieutenant, until July 1921, when he was seconded to the Royal Air Force as a flying officer. After 18 months at No. 5 Flying Training School, in December 1922 he joined No. 84 Squadron as a pilot, based in Iraq, flying DH.9As. In April 1925, he was on the staff of the RAF depot in Egypt, before joining No. 208 Squadron in January 1926. By now, Inglis had resigned his commission in the Duke of Cornwall's Light Infantry and had been appointed to a permanent commission in the rank of flying officer. On 1 July 1927, Inglis was promoted to flight lieutenant; he was immediately placed on half pay until the end of July, having recently got married. On his return to active service, Inglis joined the staff at No 4 Apprentice's Wing, RAF Cranwell. In April 1931, he transferred to the staff of the RAF College, until returning to Iraq in December 1933 as a member of the air staff, HQ Iraq Command. In January 1936, he returned to England, and attended the RAF Staff College at Andover. He was promoted to squadron leader on 1 April 1936 and to wing commander on 1 March 1939.
In January 1937, he was appointed to the staff of the deputy directorate of Intelligence, and promoted to deputy director of intelligence in 1940. In this role, he was head of the German branch of air intelligence. He was promoted to the rank of group captain in September 1941 and to air commodore in March 1942. In March 1942, he was promoted to director of intelligence, reporting direct to the prime minister, Winston Churchill. Following the entry of the United States into the Second World War, Churchill sent Inglis to see President Roosevelt to persuade him to direct the United States war effort primarily against the German air force in Europe. Inglis stayed in the White House and held two meetings with Roosevelt, eventually persuading the president to go against his own advisors and agree to the British viewpoint, that the major American war effort must be directed towards the defeat of Germany first. According to Inglis's brother-in-law, Air Marshal Sir Victor Goddard,
No other war decision by America was more significant for Europe and the World than that one. It is to be attributed to the clear trustworthiness of Frank Inglis that his vital, single-handed mission was successful, and it is to be attributed to his modesty that his part in that happening seems never to have come to the notice of historians.