During the beginning of Operation Barbarossa, the Germans had little difficulty routing the Russian Army. The Russians were simply unprepared for the high quality tanks and troops of the Germans. German over-confidence ceased when they came up against the T-34. An extremely well designed and influential tank with its roots dating back to J. Walter Christie, an American inventor, this tank was extremely formidable. German armour simply could not compete with the excellently sloped armour, the high-velocity 76.2mm gun, and the diesel engine that provided it with its uncomparable mobility. Something had to be done. The Panther was designed to meet the new Russian threat. A long, high velocity 75mm L/70 gun was placed in a sloped turret on a well armoured and highly mobile chassis. It had outstanding firepower, great mobility, and almost beautifully sloped armour. It was definitely superior to the T-34, even the 85mm gun variant. However, in spite of its qualitative superiority, the Soviets outclassed the German tanks by numbers, and, therefore, the Panther was not used to its full potential. There is some dispute about whether or not the Panther is a heavy or medium tank. It might not be a heavy tank in comparison with German and possibly even Russian tanks, but it is definitely a heavy tank by Allied armour standards.