Starting in 1950, a series of Concept Research Studies were undertaken 'in the search for a design to succeed Centurion'. A single design combining the firepower of the Conqueror's 120 mm gun with the mobility and general usefulness of the Centurion was seen as the ideal combination. However, the introduction of the Soviet IS-3 / IS-4 heavy tank along with Soviet T-54/T-55 led to the introduction of the Conqueror heavy tank armed with a 120 mm (4.7 in) gun. Its predecessor, the Centurion main battle tank (MBT), is widely considered to be one of the most successful of post-war MBT designs. The Chieftain was an evolutionary development of the successful cruiser line of tanks that had emerged at the end of the Second World War.

It remained in service until replaced by the Challenger 1 which shared many of the Chieftain's features. A new powerpack and improved transmission gave it higher speed than the Centurion despite being heavier due to major upgrades to armour protection and the armament this allowed it to replace both the Conqueror and Centurion while performing their roles effectively. The FV4201 Chieftain was the main battle tank of the United Kingdom during the 1960s–1990s.Ī development of the Centurion, the Chieftain introduced the supine (reclining) driver position to British design allowing a heavily sloped hull with reduced height.

New british main battle tank