Evolved at the RNAS base at Mudros, in the Aegean, by Lt John Alcock during the summer of 1917, the A.1 employed modified components of the Sopwith Triplane (forward fuselage and lower wings), Sopwith Pup (upper wings), and Sopwith Camel (tailplane and elevators) which were married to a rear fuselage and vertical tail surfaces of original design. Powered by a 110hp Clerget 9Z nine-cylinder rotary engine and carrying a 7.7mm Vickers machine gun, the A.1 (which was also referred to by its designers as the "Sopwith Mouse" in recognition of its part parentage) flew at Mudros in October 1917, but was written off after crashing early in 1918.