The German invasion of Russia was the biggest, bloodiest and most bitter battle ever fought. It cost the lives of at least twenty million people and ended Europe's dominance of world affairs. It was the head-on clash of the two mightiest armies man has ever known, which no other battle in history can compare with. Although Hitler's opening attack on Russia in 1941 (code named by the German Army "Operation Barbarossa") forms the climax of the narrative, this programme is concerned more with the background and build-up to the assault. Unique archive film from both sides of the Iron Curtain has been incorporated, together with notable contribution from Albert Speer, Hitler's close confidant and Munitions Chief General Warlimont, who planned the campaign and served at Hitler's headquarters throughout the War, General von Manteuffel who helped carry out the scheme and Doctor Paul Schmidt who was Hitler's individual interpreter.