The German King Tiger Tank was introduced in early 1944 and was the most powerful tank during World War II. With its powerful 88mm gun and an almost impenetrable front armor, it was one of the most feared weapons of World War II. Up to the end of the war, the allies had not introduce any effective means to counter the threat.
Although the designation implies that the Tiger II is a succession of the Tiger 1, it is in effect a completely different tank. The first design consideration for the new tank was the selection of a more effective main gun. As with the Tiger tank, it was to mount an 88mm anti tank gun but the main gun on the Tiger II was far more powerful than that on the Tiger 1.
The main gun specification of the King Tiger was to be a variation of the 88mm anti-aircraft gun. Although the 88mm was initially designed for an anti aircraft role, it proved to be an excellent tank killer.
The King Tiger's 88mm main gun has a muzzle velocity of 1000m per second when firing armor piercing rounds. It was highly accurate and able to penetrate 150mm of armor at distances exceeding 2200m. Since the flight time of an armor piercing round at a range of 2200m is about 2.2 seconds or less, accuracy and correction of fire against moving targets is more important than with older anti tank guns. This made this heavy predator ideally suited to open terrain where it could engage enemy tanks at long range before the opponent's weapons were even in range.
Besides this, the King Tiger was designed from lessons learned from battles with the T-34 with a sloped chassis.