The World War II-era Cromwell tank was still in widespread use in the early years of the Cold War and so it was decided to convert it into an upgunned tank destroyer for service with the Royal Armoured Corps. The result was the Charioteer which retained the Cromwell's hull with only minor modifications, such as the removal of the bow-mounted gun and the addition of extra armor in order to bring the hulls to Cromwell VII standard. A new turret was designed by Royal Ordinance that mounts the same 20-pounder (84-mm) gun which was used on the contemporary Centurion tank. Unlike the hull, the turret had relatively weak armor protection as it was meant that the Charioteer would be used mostly offensively. However, the size of the turret raised the Charioteer's profile considerably and even despite the size, it had very limited ammunition storage. These limitations meant that the Charioteer saw only breif service with the RAC, being phased out as early as 1956. However, it was more widely accepted abroad, where it served in the armies of Austria, Finland, Jordan, and Lebanon. Finnish vehicles were in service up until the 1970s while Lebanese vehicles saw combat during the civil war, under command of numerous warring factions.

Work on the Charioteer began in 1950 and variants were designated on the basis of their Cromwell hull, corresponding to the same mark number, these being Mk VI, Mk VII, Mk VIII; in the event all were brought up to Mk VII standard. Vehicles featuring the original 20-pdr gun were known as the Mk VIIA while those with an updated version of the 20-pdr with a fume extractor were designated Mk VIIB.