The tank has maintained its place as the centrepiece of the 20th-century battlefield ever since its introduction to overcome the trench warfare in World War I. They came into their own during World War II, mainly as part of manoeuvre warfare and the deep battle, symbolised by the Blitzkrieg and the vast enveloping manoeuvres in Operation Barbarossa. But the tank also proved its mettle in the attrition-oriented warfare as witnessed at Stalingrad and Berlin.