Beginning about mid-1942, many British tank units were equipped with vehicles supplied under lend-lease from the United States, such as the Stuart light tank, the Lee (or the British specification 'Grant' variant thereof) and the Lee's/Grant's replacement the Sherman (all these tanks received their names from the British, named after American Civil War generals; the Americans instead used their original alphanumeric designations almost exclusively until after the war). In late 1943, the British found a way to mount the QF 17-pounder anti-tank gun in the Sherman to create the Firefly, a tank with a more capable gun than the 75mm or 76mm gun normally fitted. From mid-1944, as more were produced and British designs were introduced into service the Firefly became increasingly the most common Sherman in use by the British.