Everyone has heard of The Great Escape. In March 1944, seventy-six mainly British and Commonwealth airmen tunnelled out of the PoW camp, Stalag Luft III, in Poland and escaped, triggering a vast manhunt throughout occupied Europe. Of the seventy-three subsequently recaptured, forty-one were shot by the SS in cold blood. The incident became an icon of British decency in the face of Nazi barbarity.Yet only a year later, seventy German prisoners of war,...