The IS-3, a heavy tank, developed at Experimental Plant No.100, under the leadership of M. F. Balzha in 1944-45, was the latest Soviet tank developed in the course of the Great Patriotic War.
A special commission was formed in 1943 to analyse the reasons for the horrible losses suffered by the Soviet military tank units in the Battle of Kursk (6064 machines were lost during the 38 days of battle). Based on the commission's proceedings and on the IS-2, a new heavy tank, the IS-3 was designed, this tank was considered a breakthrough design. Its hull was welded from rolled steel armour plate with the maximum possible slope on the front glacis plate. The tank was also provided with a cast gun turret, having the shape of a flattened hemisphere, which gave it a more streamlined appearance. The thickness of the frontal armour was increased considerably, owing to a reduction of armour thickness in other less vulnerable areas. Thus, the frontal armour plates of the hull were 120 mm thick, while the front of the gun turret was 230 mm thick. Having the same overall weight after the modifications, the tank had 1.5 times less frontal area. In addition this tank was equipped with a commander's control system for gun turret rotation.
Production was started in May of 1945, and continued up to mid-1946. At the end of the War 29 tanks were produced, with their total production number continuing on to 2311.
The IS-3 was not used in any military action during World War II, but on September 7th 1945 a tank regiment had taken part in the parade of Red Army Units in Berlin, being dedicated to the victory over Japan.
The IS-3 had been modernised by the end of 1950's now being named the IS-3M.
The tank was not considered an export model, although two machines arrived in Poland during 1946, while another machine arrived in Czechoslovakia with the purpose of familiarisation and instructor training. A considerably larger number of tanks were sent to North Korea, which in the 1960's had two operational regiments of IC-3's. 100 IS-3 and IS-3M heavy tanks were delivered to Egypt from 1956 to 1967.