range in the mid-1930s. From 1931 to 1938, AEC and English Electric co-produced trolleybuses. AEC supplied the chassis, and English Electric the electric motors and control equipment. In 1932, AEC took a controlling interest in the British subsidiary of the American Four Wheel Drive (FWD) company, and began to use more standard AEC components in those vehicles. To avoid confusion, these were marketed under the name Hardy. Production ceased about 1936. World War II Non-military production stopped in 1941, from then until 1944 AEC produced nearly 10,000 vehicles for the war effort. During the war, AEC produced their 10-ton 4x4 Matador artillery tractor (an adaptation of their commercial 4x2 Matador lorry that exploited AEC's experience with the Hardy FWD venture). The Matador was used for towing guns such as the 5.5-inch medium gun and the 3.7-inch AA gun. The Matador chassis was used as the basis for the Deacon a self-propelled 6-pounder anti-tank gun, which was used briefly in North Africa; A 6x6 version was designated as the "AEC Marshall" but almost always called the Matador. Four hundred AEC Armoured Command Vehicle, popularly known as the "Dorchester" (after the hotel), were built on the Matador and Marshall chassis. Production of the AEC Armoured Car started in 1941. Three Marks were built, with guns from 40mm to 75mm, totalling 629 vehicles. They remained in use post-war. Post war In 1946 AEC and Leyland Motors formed British United Traction as a joint venture to manufacture trolleybuses and traction equipment for diesel railcars since reduced demand would not require the existing capacity of both parents. In 1946 AEC resumed civilian production with the 0661/20 Regent II and the 0662/20 Regal I. These were not new models but a recommencement of the most basic AEC 1939 specification bus models. The single-decker was going to be marketed as Regal II until somebody at Southall remembered the 1936-8 lightweight 0862 model of that name and as a result the name was corrected after the launch publicity had been printed. At the end of 1946 the postwar 0961 RT was in build and by 1948 Mammoth Major, Matador and Monarch Mk IIIs were in production, followed by the 'provincial' Regent III and the Regal III. Also in 1948 AEC acquired Crossley Motors and the Maudslay Motor Company and on 1 October 1948 AEC set up Associated Commercial Vehicles (ACV) as the holding company for the newly acquired