The Royal Naval Air Service raised the first British armoured car squadron during the First World War. In September 1914 all available Rolls Royce Silver Ghost chassis were requisitioned. In October 1914 a special committee of the Admiralty Air Department among whom was Flight Commander T.G. Hetherington designed the superstructure. The first three vehicles were delivered on 3 December 1914. The vehicle was based on a Rolls Royce 40/50 hp car chassis (the engine had a maximum output of about 80 hp), to which were added armoured bodywork and a single turret for a Vickers machine gun.
The vehicle was modernized in 1920 and in 1924, resulting in Rolls-Royce 1920 Pattern and Rolls-Royce 1924 Pattern. In 1940, 34 vehicles which served in Egypt with the 11th Hussars regiment had the "old" turret replaced with an open-topped one carrying a Boys anti-tank rifle, .303 inch Bren machine gun and smoke grenade launchers.