Beginning in 1911, and until manufacturing rights were sold to Renault, Clerget, Blin, and Cie of Paris, France, built various types of airplane engines, but mainly air-cooled rotaries. During World War I, the company's effort was concentrated almost entirely on this type of engine. Gwynnes, Ltd., Hammersmith Iron Works, London, England, controlled the British manufacturing rights on Clerget engines.
The Clerget Type 9B was a highly successful engine and was used extensively during World War I. Among the French aircraft equipped with the Type 9B were the Nieuport 12 and 17, Nieuport Triplane, Pommier, Caudron, CSL, MS 30 and 35, and Spad. Numerous British aircraft were also powered by the Type 9B, among them the: Avro 504C/K/L and 531/A Spider; Bristol 10 M.1A and 11 M.1B; Cierva C.6C/D and C.8R Autogiro; and Sopwith Baby, Triplane, F.1 Camel, Scooter, Triplane, and LCT 1-1/2 Strutter.