From the 1960s to the 1990s the Chieftain Main Battle Tank was the core of the British Armoured force. Mounting a 120mm main gun, this was the replacement for the Centurion tank. 900 were produced for the British Army, and many were sold to other countries, mostly in the Middle East.
The tank was used in combat in both the Iran-Iraq War and the First Gulf War. It was not considered to be a success, and the problems (both in off road capability and resistence to Russian modern weaponry) were addrsssed in the next generation of British MBTs.