The Lanchester is a submachine gun assembled by the Sterling Armament Company, W. W. Greener and Boss & Co between 1941 and 1945. It is an evolution of the MP28/II and was manufactured in three versions, the MkI, MkI* and the MkI**. The MkI had an adjustable tangent sight, the MkI* had a two position flip sight and the MkI** was the MkI* but fitted with a bolt safety stop fitted from 1944. It was primarily used by the Royal Navy during the Second World War, and to a lesser extent by the Royal Air Force Regiment for use in their training facilities. It was given the general designation of Lanchester after George Lanchester, who was charged with producing the weapon at the Sterling Armament Company.