The T-34 is a Soviet medium tank produced from 1940 to 1958. It was the world's best tank when the Soviet Union entered the Second World War, and although its armour and armament were surpassed by later WWII tanks, it is credited as the war's most effective, efficient and influential design. First produced at the KhPZ factory in Kharkov ( Kharkiv, Ukraine), it was the mainstay of Soviet armoured forces throughout World War II, and widely exported afterwards. It was the most-produced tank of the war, and the second most-produced tank of all time, after its successor, the T-54/55 series. The T-34 was still in service with twenty-seven countries as late as 1996.