At the outbreak of the Second World War in September 1939, Miles Aircraft began work on a single-engined fighter to supplement the RAF's Spitfires and Hurricanes. A wooden mock-up of the design, the M20/1, was inspected by Sir Kingsley Wood, the Secretary of State for Air, but no orders followed. Following the outbreak of the Battle of Britain in July 1940, the Royal Air Force was faced with a potential shortage of fighters. To meet the Luftwaffe threat, the Air Ministry commissioned Miles to design a simple easy-to-build fighter to specification F.19/40. This became the Miles M.20/2. Nine weeks and two days later the first prototype flew.