By 1944, the Germans on the French Coast knew the allies were set to invade. What they didn't know was where. If they could anticipate where the Allies would land, they could mass their forces and destroy the fragile beach-head before it was even established... It was vital for the Allies to mislead the waiting Nazis about their true plans for D-Day - and so Operation Fortitude, the biggest deception of all time, was initiated. Fortitude was designed to convince the waiting Germans that the invasion would come in the Pas de Calais, and was so successful that, even after the Normandy landings were well underway, Hitler kept vital Panzer divisions in reserve in Calais, convinced the D-Day was just a diversion... D-DAY: THE SECRET BATTLE explains how this extraordinary deception was achieved, and reveals how Operation Fortitude made the invasion of Europe possible, along with other inventive deceptions including dummy parachute drops and SAS teams briefed to simulate the invasion of Calais. Equally important to the success of D-Day were two other top secret inventions - the massive floating Mulberry harbours and PLUTO - the pipeline under the ocean intended to bring vital fuel ashore. D-DAY: THE SECRET BATTLE also spotlights the top secret Allied weapons developed to assault the beach-head, including the Sherman mine-clearing 'Crab' flail tank and the terrifying British converted Churchill 'Crocodile' flame-thrower tank and includes rare film of them in action on the beaches.