The Cruiser Mk III (A13) and Mk IV (A13 Mk II) were the first British tanks to be based on the novel designs of Walter Christie in the US which had proven particularly successful in the USSR. These were characterized by the use of a unique compression-spring suspension system as well as the Liberty engine that provided excellent power to weight ratios. Limitations of the original Christie design were overcome by enlarging the hull thereby allowing a larger turret with a 2-pounder gun, which was the standard in British tanks at the time. Only a small number of the initial Mk III tanks were built before production switched to the more advanced Mk IV. This had added armor plates on the hull and turret fronts, as well as V-shaped plates on the turret sides, giving it the faceted appearance that was characteristic of its successors, the Covenanter (which also shared the A13 designation) and the Crusader. Despite the added armor, performance did not suffer due to the already high power to weight ratio in the base vehicle although by World War II standards, the design was obsolete due to weak armament and protection, reliability issues, and a design that was prone to shot traps. Still, both Mk III and Mk IV tanks were used by the 1st Armoured Division in France during the 1940 blitzkrieg, with surviving examples seeing more limited action in North Africa before being retired (Mk III) or used for training (Mk IV).

The original vehicle designed by Walter Christie was designated A13E1, with the subsequent British modified prototypes known as A13E2 and A13E3, the latter which was ready for trials in September 1937 and orders were placed the following year. In service it became known as the Cruiser Tank, Mark III (A13). Further development of the A13 resulted in the Cruiser Tank, Mark IV (A13 Mk. II). Variants included the Mk IVa with a different co-axial gun, and the Mk. IV CS with a 3.7-in mortar in place of the 2-pounder gun.