In 1919 and 1920, Frank Barnwell, chief designer of the Bristol Aeroplane Company, considered designs for a commercial transport aircraft, ranging from single-engine, three-seat aircraft to four-engine aircraft carrying ten passengers, none of which were built. Early in 1921, the British government decided to provide subsidies for approved airlines, so Bristol's management authorised Barnwell to proceed with a design for a single-engined transport aircraft. It was intended to be powered by a Bristol Jupiter engine, but this had not yet been type-approved, so the initial prototype was fitted with a Napier Lion engine instead.