From the early stages of Operation Barbarossa the Wehrmacht became aware that their ability to combat some of the Soviet tanks was inadequate. The lighter tanks then in general service, such as the Panzer II and the Czech built 38(t), were under-armoured and did not mount an adequate gun to deal with the newer Soviet tanks. In addition, the standard towed anti-tank gun of the Wehrmacht, the 37 mm Pak 36, was both difficult to get into position quickly and lacked the ability to penetrate the heavy sloped armour of the new Soviet tanks.