From the start of World War Two, Britain's Royal Air Force had stood alone. Following the attack on Pearl Harbour and America's entry into the conflict, the arrival of the 8th US Army Air Force in England began to turn the tide. This programme tells the story of the Allied bombing campaign over northern Europe, as they pounded the heart of German-occupied Europe with the use of Liberators and Flying Fortresses by day and Lancasters by night. In the Mediterranean the siege of Malta was lifted and the invasion of Italy brought most of southern Europe within range of Allied air power. In the East, Soviet air forces first checked and then drove back the Nazi invaders to the gates of Berlin. After D-Day, American warplanes fought a war of attrition against the once-mighty Luftwaffe and successfully achieved air supremacy over Europe.