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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The arsenal of weaponry employed during the course of the war, beginning with tanks, the mainstay of the Nazis' fearsome Blitzkrieg strategy. In 1939, a Mark 3 Panzer corps entered Poland, setting Europe on an irrevocable path to conflict as country after country fell into German hands.

From attacks on Pearl Harbor and Sydney Harbour, to the British Mediterranean Fleet and the Tirpitz, midget submarines played their part in some of the most gripping stories of the war. This programme recalls the heroic encounters of the men who piloted these midget craft towards their giant quarries.

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The crucial part played by aircraft carriers in the war, first developed by the Royal Navy at the end of World War One to supersede battleships. After a successful British carrier-based attack on the Italian fleet, the Japanese resorted to the tactic of wreaking havoc on Pearl Harbour - only to face devastating retaliation from the US, who ended the war in an unrivalled position of maritime dominance.

By 1944, the Allied fronts in both western and eastern Europe had become faster moving and a new form of aircraft was needed to deliver swift, powerful attacks against German lines. This programme looks at the key fighter-bombers on all sides, including the American Thunderbolt, the Russian Sturmovik, and the British Hurricane developed to carry bombs and rockets for ground attack purposes.

At the outbreak of World War II, the only heavy four engined bombers in the war were either Russian or American. Soon the Short Stirling, the Avro Lancaster, and the Liberator were added to the B-17 Flying Fortress for devastating 1000 bomber raids over Germany. Ultimately, the pressurised B-29 gave the Americans the range and height they required in order to drop the Atomic bomb.

How battleships lost their naval supremacy during the conflict because of their vulnerability to aerial attack. The pride of the German Navy, the Bismarck, was crippled by Swordfish torpedo aircraft, while the state-of-the-art HMS Prince of Wales was sunk in the Pacific by Japanese planes.

The development of Germany's V1, or doodlebug, and more sophisticated V2 rocket, both of which were used during the latter stages of the conflict to strike at the very heart of British life and undermine morale on the home front.

Fast patrol boats, armed with torpedoes and machine guns, were the marine raiders of World War II. This programme looks at some of their most spectacular raids, as well as the incident involving future President of the United States, John Kennedy, in a clash with a Japanese destroyer.

The development of machine guns, including the Thompson, which was favoured by American gangsters during the 1920s. Plus, the lowdown on the Anglo-Czech Bren and various Russian models.