In December 1915, some 135,000 allied troops, nearly 400 guns and 15,000 horses were collectively trapped in the bridgeheads at Anzac, Suvla and Helles. It was clear that the operation to seize control of Dardanelles and the Bosporus straits and capture Constantinople (now Istanbul) from the Turks, and thereby open a Black Sea supply route to Russia, had failed. With every day that passed the Turks moved up more guns, threatening to blast to pieces the flimsy piers, breakwaters and blockships that acted as makeshift harbours to feed and supply tens of thousands of men. And winter was coming. The evacuation plans were brilliant, but it was still a close-run thing. A spell of bad weather in the final days might have destroyed the flimsy piers, leaving thousands trapped helpless should the Turkish guns open up and their infantry swarm over No Man's Land. Dan and historian Peter Hart discuss this story of how the Gallipoli garrison escaped to fight another day. Peter Hart was an oral historian at the Imperial War Museum for almost 40 years, during that time he interviewed thousands of veterans. An internationally acknowledged expert on Gallipoli, he is uniquely well placed to tell this remarkable story.