In 1937, the Red Army had assigned engineer Mikhail Koshkin to lead a new team to design a replacement for the BT tanks at the Kharkiv Komintern Locomotive Plant (KhPZ). Both were Soviet developments of foreign designs from the early 1930s the T-26 was based on the British Vickers 6-Ton, and the BT tanks were based on a design from American engineer J. The BT tanks were cavalry tanks: fast-moving and light, designed for manoeuver warfare.

The T-26 was slow-moving, designed to keep pace with infantry on the ground. In 1939, the most numerous Soviet tank models were the T-26 infantry tank and the BT series of fast tanks. T-34 variants were widely exported after World War II, and as recently as 2010 more than 130 were still in service. Its development led directly to the T-44, then the T-54 and T-55 series of tanks, which in turn evolved into the later T-62, that form the armoured core of many modern armies. With 44,900 lost during the war, it also suffered the most tank losses ever. Replacing many light and medium tanks in Red Army service, it was the most-produced tank of the war, as well as the second most-produced tank of all time (after its successor, the T-54/T-55 series). The Soviets ultimately built over 80,000 T-34s of all variants, allowing steadily greater numbers to be fielded despite the loss of tens of thousands in combat against the German Wehrmacht.

Its production method was continuously refined and rationalized to meet the needs of the Eastern Front, making the T-34 quicker and cheaper to produce. Its general specifications remained nearly unchanged until early 1944, when it received a firepower upgrade with the introduction of the greatly improved T-34-85 variant. The T-34 was the mainstay of the Soviet Red Army armoured forces throughout the war.

The tank was praised by multiple German generals when encountered during Operation Barbarossa, although its armour and armament were surpassed later in the war. The T-34 had a profound effect on the conflict on the Eastern Front, and had a long-lasting impact on tank design. When introduced, its 76.2 mm (3 in) tank gun was more powerful than its contemporaries, and its 60-degree sloped armour provided good protection against anti-tank weapons. The T-34 is a Soviet medium tank from World War II.

Surface go model 1943