From the outset it was an almost impossible task, a suicide mission: to fly low and at night in formationover many miles of enemy-occupied territory at the very limit of the Lancasters' capacity, and drop a new weapon that had never been tried operationally before from a precise height of just sixty feet from the water at some of the most heavily defended targets in Germany.
More than that, the entire operation had to be put together in less than ten weeks. When visionary aviation engineer Barnes Wallis's concept of the bouncing bomb was green lighted, he hadn't even drawn up his plans for the weapon that was to smash the dams. What followed was an incredible race against time, which, despite numerous setbacks and against huge odds, became one of the most successful and game-changing bombing raids of all time.
James Holland is an internationally acclaimed and award-winning historian, writer, and broadcaster. The author of a number of best-selling histories including most recently The Savage Storm and Cassino '44, he is also the author of ten works of fiction and a dozen Ladybird Experts.
He is the co-founder of the annual Chalke Valley History Festival which is now in its twelfth year, and he has presented - and written - many television programmes and series for the BBC, Channel 4, National Geographic and the History and Discovery channels.
With Al Murray, he has a successful Second World War podcast, We Have Ways of Making You Talk, which also has its own festival, and is a research fellow at St Andrew's University and a Fellow of the Royal Historical Society. He can be found on Twitter as @James1940 and on Instagram as @jamesholland1940.