The IS-3 ("IS" for "Iosef Stalin" or "Josef Stalin") was an attempt to build upon the already formidable IS-2. Improvements over the IS-2 model included a redesigned rounded turret and a new heavily-sloped front armor configuration. The base 122mm (121.9mm D-25T) 4.8 inch main gun was retained as was the superior armor protection afforded to both crew and tank. The IS-3 was produced in limited numbers by war's end, but the system would still see service in other Soviet-supported countries and retain the title of "most powerful tank in the world" for years.
