1939–1945, Zaloga and Ness, pp. 65–68). These would be the armored formations which would attempt counter strikes against the German invasion. The performance of these corps was generally not good and they were officially disbanded in mid-July, 1941 (Ibid., p. 70). Additional information on these formations can also be found in Soviet Order of Battle World War II, Vol. I, by Charles C. Sharp. Eastern Front of World War II On 31 March 1942, orders were given for the reformation of the tank corps, as a result of the Soviet need for massed armored units so that the small tank brigades, which were now the basic armored formation, could be capable of decisive actions. The 1st, 2nd, 3rd, and 4th Tank Corps were to consist of a headquarters, two tank brigades, and a motor rifle brigade, authorized a total of 5,603 men with 20 KV heavy tanks, 40 T-34 medium tanks, and 40 T-60 or T-70 light tanks. The new tank corps lacked artillery, reconnaissance and engineer units, and rear support elements, although its component brigades included such formations. They were the equivalent of small Western armored divisions. The motor rifle brigade was a new unit type intended to retain captured positions and to neutralize enemy infantry and anti-tank weapons. It was determined that this was too weak, and a third tank brigade was added to increase the offensive power. The final organisation as published in 1944 included an additional heavy tank or heavy self-propelled gun regiment, plus a medium and a light self-propelled gun regiment. A total of 31 tank corps were formed during the war, with 12 of them earning the designation of a Guards Tank Corps. Due to the destruction of the 21st Tank Corps at the Second Battle of Kharkov and the use of some tank corps to form mechanised corps, no more than 24 of them actually saw combat. The tank corps were the basic building block of the Tank Armies (see List of Soviet armies#Tank Armies). Most tank corps were converted to Tank Divisions in 1945–6. See List of Soviet Army divisions 1989-91. List of tank corps (19411945) 1st Tank Corps 2nd Tank Corps 3rd Tank Corps – renamed 9th Guards Tank Corps after Battle of Radzymin (1944). 4th Tank Corps – March 1942 – February 1943 – converted to 5th Guards Tank Corps 5th Tank Corps – formed April 1942. Equipped largely with