The Lanchester Model 1 was an experimental submachine gun designed by George Lanchester and manufactured by Sterling Armaments Co.
After the adoption of the Lanchester Mk.I submachine gun by the British Royal Navy and Air Force, George Lanchester began work on another submachine gun. The result was a light, all-metal submachine gun, which internally was very similar to his previous weapon, but with a modified trigger mechanism. The fire selector only had "semi" and "auto" firemodes; the Lanchester cocking slot had a rear safety position that held the bolt back when retracted. The weapon had a cylindrical horizontal foregrip made of Tufnel. Essentially the finished product was nothing more than a stripped-down Lanchester Mk.I. Oddly enough, the initial prototype had holes in the rear end to allow a folding stock to be attached, but there are no records of the weapon ever having a stock.
The design was later improved in the form of the Lanchester Model 2, which had an improved body with left-handed cocking and a new lighter and shorter bolt. It also had a small multi-piece extractor consisting of a claw and spring. A separate firing pin was fitted around the return spring. The safety system of the first prototype was removed, and instead a more conventional method of safety was implemented which was controlled via the fire selector. A new foregrip was fitted, which was made from wood, and was shaped to offer ergonomic improvements, although the pistol grip was still made from Tufnel. A folding stock was added.
Both prototypes were tested by the British Army and performed perfectly fine, but the Army was already considering the STEN and had no need for Lanchester's submachine guns. The prototypes were kept in storerooms at Sterling Armaments Co. until 1972.