Timewatch

Documentary that reveals the secret story behind one of the greatest intellectual feats of World War II, a feat that gave birth to the digital age. In 1943, a 24-year-old maths student and a GPO engineer combined to hack into Hitler's personal super-code machine - not Enigma but an even tougher system, which he called his 'secrets writer'. Their break turned the Battle of Kursk, powered the D-day landings and orchestrated the end of the conflict in Europe. But it was also to be used during the Cold War - which meant both men's achievements were hushed up and never officially recognised.

Lord Ashdown, a former special forces commando, tells the story of the 'Cockleshell Heroes', who led one of the most daring and audacious commando raids of World War II. In 1942, Britain was struggling to fight back against Nazi Germany. Lacking the resources for a second front, Churchill encouraged innovative and daring new methods of combat. Enter stage left, Blondie Hasler. With a unit of twelve Royal Marine commandos, Major Blondie Hasler believed his 'cockleshell' canoe could be effectively used in clandestine attacks on the enemy. Their brief was to navigate the most heavily defended estuary in Europe, to dodge searchlights, machine-gun posts and armed river-patrol craft 70 miles downriver, and then to blow up enemy shipping in Bordeaux harbour. Lord Ashdown recreates parts of the raid and explains how this experience was used in preparing for one of the greatest land invasions in history, D-day.

James Holland presents an analysis of the legendary 1943 Dam Busters raid, a low-level night mission that took 19 Lancaster bombers deep into the heart of enemy territory to destroy German dams with a brand new weapon - the bouncing bomb. Of the many extraordinary things about the Dams raid, the biggest is that it almost never happened. When finally green lit, it set off an incredible race against time to form and train a new squadron. Their mission was to deliver a weapon that did not yet exist. Unprecedented by any scale, and even more remarkable because the crews were not the experienced elite that legend sometimes suggests, Holland believes this truly is the greatest raid of all time. Yet, whilst arguing that the true impact of the successful raid has been underestimated, he also sets out to investigate whether the results should have been even greater.

Following on from his hugely successful BBC2 documentary, Operation Mincemeat, based on his book of the same name, writer and presenter Ben MacIntyre returns to the small screen to bring to life his other bestselling book - Agent Zigzag. As part of the Timewatch series, MacIntyre reveals the gripping true story of Britain's most extraordinary wartime double agent, Eddie Chapman. A notorious safe-breaker before the war, Chapman duped the Germans so successfully that he was awarded their highest decoration, the Iron Cross. He remains the only British citizen ever to win one. Including remarkable and newly discovered footage from an interview Chapman gave three years before his death in 1997, the programme goes on the trail of one of Britain's most unlikely heroes - a story of adventure, love, intrigue and astonishing courage.