The Lanchester is a British 9×19mm Parabellum submachine gun manufactured by the Sterling Armaments Company between 1941 and 1945. It is a copy of the German MP28/II. It was primarily used by the Royal Navy during World War II, and to a lesser extent by the Royal Air Force Regiment (for airfield protection). The weapon took its name after George Herbert Lanchester, who was charged with producing the weapon at the Sterling Armaments Company.
The Lanchester had a heavy wooden buttstock, a machined-steel action and breech block, a magazine housing made from brass (later steel) and a mounting on the muzzle for use of a long-bladed 1907 bayonet. The weapon was produced in two versions, Mk.1 and Mk.1*. The Mk.1* has no fire selector (full-auto only) and has simplified iron sights.