General of the Air Force (GAF) is a five-star general officer rank and is the highest possible rank in the United States Air Force. General of the Air Force ranks immediately above a general and is equivalent to General of the Army in the United States Army and fleet admiral in the United States Navy. The rank has only been held by one man, General Henry H. Arnold, who had served as head of the United States Army Air Forces during World War II. As at the time of his promotion, the Air Force was a component of the Army instead of its own branch, and as a consequence, the rank has not been first awarded to someone who is serving in the Air Force. Arnold retained the rank when the separate branch was created, and he was redesignated General of the Air Force in 1949.