The Rolls-Royce Phantom was introduced in 1925. First introduced as the "New Phantom," the first generation of Phantom has become known as the Phantom I. Rolls-Royce never officially titled it the 'I,' but the name has become standard to help differentiate it from other generations. As was standard at the time, Rolls-Royce only constructed the fully functioning chassis. The bodywork was done by handful of coachbuilder depending on the buyer's choice. The Rolls-Royce Phantom I featured a 7.7L inline six engine, and was in production until 1931. The Phantom I was replaced by the Rolls-Royce Phantom II.