The KV heavy tank (Klim Voroshilov) at the beginning of the Great Patriotic War was, of course, the most advanced in design and the most powerful tank in the world. It was created specifically to break through fortified defense lines, had very strong weapons for its time, and its armor could not be penetrated by any of the Wehrmacht anti-tank guns. German tanks in a duel with the KV had no chance at all to emerge victorious, which forced the Reich designers to urgently begin designing the Tiger and Panther. In the Red Army, tanks of the KV family (KV-1, KV-1S, KV-2, KV-8 and KV-85) fought on all fronts from the first days of the war until 1944, when they were replaced by the famous IS-2. The latter, by the way, represented a deep modernization of the same HF. However, all the heavy tanks that appeared in different countries during the Second World War were, in one way or another, created with an eye on “Klim Voroshilov” - one of the most successful projects in the history of domestic tank building.