Radar gave British air defence the edge during the Battle of Britain and helped save Britain from invasion. But who were the electronic boffins behind its development in the 1930s and 40s? This programme reveals the technological race between Britain, Germany and America to create the most effective radar and how radar also helped Britain defeat the U-boat menace.

The Spitfire is perhaps the most famous fighter plane of World War II, being a key element in winning the battle of Britain. But who designed it? R J Mitchell was a sickly inventor who created the Vickers Supermarine Schneider trophy-winning seaplane of the 1930s. It was this aircraft which was transformed into the battle-winning Spitfire just weeks before its inventor died.

In April 1945, British troops walked through the gates of Belsen, the notorious concentration camp. What they saw shocked the world. Richard Dimbleby and other Allied correspondents made sure through radio broadcasts and unique film footage that the world knew about the dreadful crimes committed by Hitler and his Nazi henchmen.

In 1940, German bombers were ready to bomb Britain into submission and they were aided by the use of radio beams which told them exactly where to drop bombs at night. Dr R V Jones of British Air Intelligence was tasked with defeating this high-tech warfare. Ingeniously, he devised counter-beams which put the Germans off target.

By 1944, German generals could see that Hitler was leading them on a path to destruction, but who would stop him? In July 1944, Colonel Count Claus von Stauffenberg placed a bomb in a briefcase beside Hitler. The room exploded and Stauffenberg made his escape, thinking Hitler was dead. But the dictator was not and savage retribution followed.

Enigma was the encoding machine of the German army - break the code and you could win the war. Polish agents sent a captured machine to the British and at Bletchley Park, using the genius of men like Alan Turing, a team of cryptanalysts broke its code, giving valuable advanced intelligence to the Allies throughout the war.

Completed in 1940, the Bismarck was widely regarded as the most powerful warship in the world. In April 1941, Admiral Tovey of the British Royal Navy detected an attempt by the Bismarck to break out into the Atlantic and the hunt was on. In a first battle, the Bismarck sank HMS Hood. But Tovey used radar to track her down again and finally she was surrounded by British heavy warships and pounded into submission.

At first, Allied bombing raids on Germany were highly inaccurate, but then an elite force of night-bomber navigators were trained. They flew before the main bombing raids, marking targets with different coloured flares. It was highly hazardous work, but helped make Allied bombing raids significantly more effective.

How could one dead man save the lives of thousands of Allied soldiers? Ewen Montagu knew how and devised a cunning deception in which the body of a dead officer was washed ashore in Spain with false information about Allied landings in the Mediterranean. Hitler took the bait and was poorly prepared for the Allied invasion of Italy. NMP has uncovered exclusive new information on the identity of the body.

In 1944 the Allies knew that they must invade Occupied Europe to free millions from Nazi tyranny. But the Nazis knew they were coming. The only question was when the attack would take place, and where. This programme reveals the inventive and often bizarre methods that were used to mislead the Nazis. Double agents spread bogus invasion plans, fake armies were mustered in the south of England and elaborate methods of breaking through Hitler's Atlantic wall were developed.