The first comprehensive illustrated history of a remarkable Victorian mansion in Buckinghamshire that played such an important role in British history. From its prewar heyday as a country estate under the Liberal MP Sir Herbert Leon, through its wartime requisition with the addition of the famous huts within the grounds, to become the place where modern computing was invented and the German Enigma code was cracked, its post-war dereliction and then rescue towards the end of the twentieth century as an engrossing museum of wartime codebreaking whose visitor numbers have more than doubled in the last five years. Featuring over 200 photographs, some previously unseen, this is a complete and comprehensive guide to a country estate that played in pivotal role in winning the war against the Nazis.