The IS Tank was a series of heavy tanks developed as a successor to the KV-series by the Soviet Union during World War II. The heavy tanks were designed with thick armour to counter German 88 mm guns and carried a main gun capable of defeating Tiger and Panther tanks. They were mainly designed as breakthrough tanks, firing a heavy high-explosive shell that was useful against entrenchments and bunkers. The IS-2 went into service in April 1944 and was used as a spearhead by the Red Army in the final stage of the Battle of Berlin Designer M Bergman
