Operation Citadel, Hitlers attempt to 'pinch out' the Kursk salient, was his last great offensive on the Eastern Front. It became the greatest clash of armour the world had ever seen, and both armies knew that this was a pivotal battle of World War 2. If the German Panzer armies under Erich von Manstein - reinforced with the latest Tiger tanks - could break through, more than half a million Soviet troops would be cut off. If Nikolai Vatutin's men could hurl them back, then a resurgent Red Army could seize the initiative for a series of relentless offensives.