There is no reason why you should have heard of Geoffrey Pyke. After his suicide in 1948 he was described as one of the great geniuses of his time, to rank alongside Einstein, yet he remains today, as The Times put it, 'one of the most original if unrecognised figures' of the twentieth century. Inventor, escapee, campaigner, war correspondent, Pyke was an unlikely hero of both world wars and is seen today as the father of the U.S. Special Forces. He changed the landscape of British pre-school education, earned a fortune on the stock market, wrote a bestseller and in 1942 convinced Churchill...