Design work began shortly after the start of the First World War following meetings between Captain Murray Sueter, the director of the Air Department of the Royal Navy, and Frederick Handley Page. Sueter requested "a bloody paralyser of an aircraft" for long-range bombing. The phrase was originated by Commander Charles Rumney Samson, who had recently returned from the front. Coastal patrol adaptations of the abortive Handley Page L/200, M/200 and MS/200 designs were initially discussed but Sueter's technical advisor favoured a large seaplane for coastal patrol and dockyard defence that would also be capable of bombing the German High Seas Fleet at its base in Kiel. The AD Seaplane Type 1000 prototype had already been commissioned from J. Samuel White & Co. of Cowes.