Juan Pujol Garcia, code-named "Garbo," is considered one of the heroes of D-Day. But he didn't land on the beaches of Normandy in 1944 nor fight on the front lines of World War II.

The Spaniard was a double agent, a supposed Nazi spy who was actually operating in the employ of the British. Based in London by the latter stages of the war, he presided over an illusory spy network that fed faulty intelligence to the Third Reich. Pujol's most famous accomplishment: In June 1944, his missives managed to convince Hitler that the planned Allied invasion of Normandy was a trick, and that the Germans should concentrate their military strength in Pas de Calais, along the Belgian border.

That ruse may have turned the tide of battle, enabling British and American forces to establish a foothold in France while the bulk of the German divisions were 150 miles away.

"The German Fifteenth Army, which, if committed to battle in June or July, might possibly have defeated [the Allies] by sheer weight of numbers, remained inoperative throughout the critical period of the campaign," wrote Supreme Allied Commander (and later U.S. President) Dwight D. Eisenhower.

But, as newly declassified British documents at Britain's National Archives reveal, it could have gone horribly wrong had Pujol's then-wife had her way. Reports kept by MI5, Britain's domestic counterintelligence agency, indicated that, by mid-1943, Araceli Gonzalez was getting increasingly exasperated with life in London, homesick for Spain and her mother and eager to quit ol' Blighty.

"I don't want to live five minutes longer with my husband," she is documented shouting at Pujol's MI5 case officer, Tomas Harris. "Even if they kill me I am going to the Spanish Embassy." Had she done so, British authorities feared, Pujol's mission would be totally compromised. Spain's fascist government, while technically a nonbelligerent during World War II, had obvious ties to the Axis powers.

The newly declassified documents show how Pujol and his British handlers managed to subdue his wife's protestations through coercion and deception. The language used to describe Gonzalez's demeanor is unkind. She was 23, living in a tiny flat in gray and war-ravaged London, spoke little to no English, and was coping with a newborn while her husband was gone most hours of the day.

"She is a highly emotional and neurotic woman and therefore I have never definitely disillusioned her in her hopes that she might be allowed to see her mother before the termination of the war," Harris wrote. Other documents indicate that British officials attempted to calm Gonzalez with a present of silk stockings, which were in short supply during wartime.

They placed a watch on the Spanish Embassy to intercept her if she attempted to reach it. And then they cooked up a hoax with the willing participation of her husband, who pretended to be arrested by the British as a consequence of the security threat his wife posed. He was only "released" after Gonzalez issued a statement under British supervision that she would "not do anything in future to jeopardize the work being done by her husband or cause embarrassment" to the British intelligence services.

According to notes made by Harris, she was scolded dismissively by an MI5 lawyer: "He reminded her that he had no time to waste with tiresome people and that if her name was ever mentioned to him again, he would simply direct that she should be locked up," the case officer wrote. "She returned home very chastened to await husband's arrival."

Seven decades later, it's hard not to see the whole mini-drama as a rather pathetic series of events. A blog post on the National Archives website concurs: "At the height of a bloody conflict it is easy to understand why Garbo and MI5 took such a tough line, but it is difficult not to feel sympathy for Mrs. Garbo, and admiration for her role in one of the greatest deceptions of the 20th century."

After all, she was instrumental in her husband's somewhat bizarre career in espionage. Pujol, considered by later historians to be more a con artist than an idealist, had managed to first install himself in Lisbon and get into the good graces of German military intelligence, with whom he started sharing invented information. Gonzalez was perhaps the better spy of the pair, as the National Archives blog post notes:

Garbo, unlike virtually all other Double Cross agents, was not originally a German spy. Instead he started out on his own, working in Lisbon, feeding the Germans information he made up from the few maps and guide books he had available. Garbo’s wife, Araceli, played a vital role in the setting up of this deception. She personally delivered some of Garbo’s earliest messages and through some excellent acting helped convince Garbo’s German handlers that he was spying in England, when in fact he was living quietly in Portugal.

Pujol's capacity for dissembling was what earned him the moniker "Garbo," the last name of the famous American actress Greta.

He and his wife were later removed to London once the British had brought him into their fold. Pujol and Harris set about creating a fictional network of agents supposedly aiding his snooping for the Nazis; his work was so convincing that the Third Reich even awarded its favored British operative the Iron Cross, a Nazi recognition of combat service, in July 1944.

The couple's story after World War II did not have a happy ending. They divorced. Fearing Nazi vengeance, Pujol enlisted MI5 to help fake his death from malaria in 1949 in the jungles of Angola. He then disappeared for decades, only resurfacing in the public eye in 1984 in Venezuela, where had lived in relative anonymity with a second wife and three more children. Pujol died in Caracas in 1988.

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