The A27M Cromwell, and the related A27L Centaur, were one of the most successful series of cruiser tanks fielded by Britain in the Second World War. The Cromwell tank, named after the English Civil War leader Oliver Cromwell, was the first tank put into service by the British to combine a dual-purpose gun, high speed from the powerful and reliable Meteor engine, and reasonable armor, in a balanced package. Its design formed the basis of the Comet tank.
The Cromwell and Centaur differed in the engine used. While the Centaur had the Liberty engine of the predecessor cruiser tank, the Crusader] (and the interim Cavalier), the Cromwell had the significantly more powerful Meteor. Apart from the engine and associated transmission differences, the two tanks were the same and many Centaurs were later fitted with the Meteor to make them Cromwells.