The Tank, Cruiser, Challenger (A30) was a British tank of World War II. It mounted the QF 17-pounder anti-tank gun on a chassis derived from the Cromwell tank to add anti-tank firepower to the cruiser tank units. The design compromises made in fitting the large gun onto the Cromwell chassis resulted in a tank with a powerful weapon and reduced armour. The extemporised 17-pounder Sherman Firefly conversion of the US-supplied Sherman was easier to produce and, with delays in production, only 200 Challengers were built. The Challenger was able to keep up with the fast Cromwell tank and was used with them.