On 13 September 1940, 80,000 Italian troops marched out of Libya into Egypt to threaten the epicentre of the British Empire at a critical moment in the Second World War. And what began as a desert skirmish rapidly became the fulcrum of Britain's struggle for survival against the Nazis. / This obscure wilderness, of no apparent strategic value, was the scene of Winston Churchill's lonely stand against the seemingly overwhelming forces of the German-Italian fascist Axis. / By 1942 the battle for North Africa had become pivotal to what was by then a truly global conflict, with hundreds of thousands of men from at least 10 nations fighting on one of the most inhospitable battlefields on Earth, culminating in the Battle of El Alamein, 70 years ago. It was a triumph that marked, in Churchill's famous words, 'the end of the beginning'. / This is the story of how the men who fought and died here were players in a high drama scripted by Churchill, Roosevelt, Mussolini and Hitler in the war capitals of London, Washington, Rome and Berlin. To tell this compelling story Jonathan Dimbleby travels to all the key locations, among them the Cabinet War Rooms deep beneath Whitehall, the vast bunker in Poland where Hitler plotted his campaigns, the tunnels under Malta where civilians sheltered from the Nazi bombs, the Brenner Pass where Hitler and Mussolini planned their campaign and to El Alamein itself where the battle reached its climax. (Source: BBC)