The Sopwith Cobham was designed to meet a June 1918 requirement for a twin-engined long-range medium bomber to equip the Royal Air Force (to meet RAF Type IV, VI and VII specifications).
It was designed to be powered by two of the new ABC Dragonfly radial engines, which promised high power for low installed weight, and had been ordered in large numbers to equip most of the prospective types planned to equip the RAF.
[1] It had a crew of three, with a pilot sitting in a cockpit just forward of the leading edge of the wings, while gunners sat in nose and dorsal positions, each armed with Lewis guns on Scarff rings.
It was later re-engined with more-powerful, high compression Pumas, rated at 290 hp (220 kW), being tested at RAF Martlesham Heath in March 1920.
As they were heavier than expected, the design had to be modified with the engines mounted further back and the stagger on the wings adjusted.