In 1940, a Danish citizen named Wulf Schmidt parachuted into Britain. He was part of an espionage campaign launched against Britain by the Abwehr, German intelligence. The spies were sent to Britain by parachute or submarine, or entered the country on false passports or posing as refugees.

Schmidt’s landing did not go smoothly. As he jumped, he hit his wrist and shattered his watch. He also got caught up in some telegraph wires and, when he untangled himself, he dropped to the ground and twisted his ankle.

The next morning he made his way into nearby Willingham, where he bought a new watch and a copy of The Times, and had breakfast in a café. People saw straight through his disguise; he was, after all, a stranger who had turned up out of nowhere one day, and though his English was good his voice was still accented. He was quickly arrested.

Neither Schmidt nor the officers who arrested him could have known that he would go on to become one of the most successful double agents in history, working for Britain against Nazi Germany. While carrying out his deceptions, he lived in England and worked as a photographer for the Watford Observer.

At the time of Schmidt’s landing, “spy-mania”, as Churchill called it, was rife in Britain. Many believed that the country was full of well-trained German spies who were deeply integrated into society.

However, this was completely untrue. The few spies that were sent by Germany were badly trained and poorly motivated. In fact, post-war records confirmed that none of the Abwehr agents, bar one who committed suicide, went unnoticed. The Abwehr had overestimated their capabilities and underestimated their enemies. By 1941 British code-breakers at Bletchley Park had managed to decipher the Abwehr hand cypher, and all of the wireless transmissions of field agents could be read. In early 1942 the Enigma machine code was also broken; thus all secret radio messages were intercepted. German spies became easy to locate.

Once caught, the spies were taken to Latchmere House in Richmond. They were interrogated by Lieutenant Robin Stephens, who picked apart their life history. Afterwards, they were spirited away to be imprisoned or executed, or, if deemed acceptable, they were offered the chance to turn double on the Germans. If they agreed, they were then used by the British to broadcast disinformation to their Nazi controllers.

Schmidt resisted interrogation for 13 days. But then he was told that his friend, Gosta Caroli, who had been captured before him, had sold him out. Schmidt swapped sides in anger. In fact, Caroli had been coerced into turning double in return for Schmidt’s life being spared.

Schmidt became known as Harry Williamson, though his codename was Tate, supposedly because he resembled music hall comedian Harry Tate.

He participated in the Operation Bodyguard deception, which covered the Invasion of Normandy. Once Normandy had been chosen as the site of the invasion, it was decided to attempt to deceive the Germans into thinking it was a diversion and that the true invasion was to be elsewhere. The operation succeeded. The deception suggesting that the Normandy landings were a diversion led Hitler to delay sending reinforcements for nearly seven weeks.

After U-Day, Schmidt was set the new task of deceiving the enemy about the accuracy of their V-1 doodle bug flying bombs.

The Abwehr is considered to have been largely ineffective. Most of its intelligence was deemed politically unacceptable to the German leadership. There was also plenty of conflict between the Abwehr and the SS, as many operatives for the Abwehr were in fact anti-Nazi. They were even involved in assassination attempts against Hitler.

Schmidt became one of the longest running agents in the Double Cross System, under which all German agents in Britain were controlled by MI5. He transmitted more than 1,000 encoded messages by radio, more than any other agent in England, during his five years as a spy. The Nazi authorities were so impressed by the information they were getting from him that he was made a naturalised German by radio. He has been singled out as one of the spies who changed the world.

After the war he lived quietly with his English wife and daughter, until publicity over an unpaid poll tax bill led to revelations about his past.

He died in Watford at the age of 80 in 1992.

Information courtesy of Jon Edney of www.oldwillingham.com