This is the Second World War career of the longest serving double agent in the Double Cross system, Harry Williamson. Harry operated from September 1940 to the end of war after initially being parachuted into England by the Nazi secret service, the Abwehr. He was quickly caught and taken to Camp 020 for interrogation by the team led by the famous Colonel ‘Tin-Eye’ Stephens. He eventually agreed to work as a double agent with the cover name TATE and went on to send more than a thousand messages during the war for the Double Cross organization, who’s aim was to supply disinformation to the Nazi regime. Harry took part in the famous D-Day deception, provided the Nazis with misinformation about the damage caused by the V1 and V2 rockets and misled the German Navy with faulty intelligence over U-boat minefields, critical to the success of British convoys. After the war he settled in Watford and worked as a photographer. He was almost completely anonymous (although still protected by MI5), partly through fear of revenge, until his name was revealed in the 1990s.