The Chieftain was an evolutionary development of the successful cruiser line of tanks that had emerged at the end of the Second World War.
Its predecessor the Centurion main battle tank is widely considered to be one of the most successful of post-war MBT designs.
The tank was expected to be able to engage the enemy at long range, from defensive positions, and be proof against medium artillery.
To this end the gun was to have a greater angle of depression than the 8 degrees of Conqueror and would be equipped with better frontal armour.
This was further hampered by the Horstmann coil spring suspension, which made it a challenge to drive cross country and provide the crew with a comfortable ride.