Development of the aircraft began during the Second World War in 1943 as an aircraft suitable for combat that harnessed the new innovation of jet propulsion; it was quickly decided to opt for a single-engine, twin-boom aircraft equipped with the Halford H.1 turbojet engine, which was later known as the de Havilland Goblin. Originally ordered as an experimental aircraft only, the decision to mass-produce the aircraft as an interceptor for the Royal Air Force (RAF) was finalized in May 1944.