A prolific sub-contractor building airframes during the First World War, Boulton & Paul entered thefield of design and manufacture in 1917 with the formation of an Aeronautical and Research Divisionunder John Dudley North. Never destined to be one of the big players, they produced a relativelymodest output of prototype aircraft and then in 1937 a series of bombers and a small batch ofcivilian two seaters. The relatively unsuccessful Defiant was their best known aircraft.However, hidden from public view was a prolific output of proposals, trials and inventions. Frombiplane fighters through the novel turret fighters and into the supersonic age with VTOL lift-fan jets, Boulton Paul were always at the forefront of development.Based upon over 60 years of research, this book recounts many of these radical and innovativeprojects using development layouts, final schemes, drawings and photographs of mock-ups, modelsand prototype airframes. Many projects are recreated in CAD and other drawings by the authorpreviously an apprentice and a technical engineer with the company and archivist of the BoultonPaul Association.This book sheds much new light on the activities of a hitherto often overlooked company which wasin many respects at the forefront of aeronautical innovation in Britain for several decades.