When Dutch-born Margaretha Zelle MacLeod (1876–1917) was arrested in Paris on February 13, 1917, there was scant hard evidence that this woman, known throughout Europe as Mata Hari, was actually a spy for the Germans during World War I (1914–18); but there was plenty of evidence that she had long consorted with the enemy and had been paid by them, but for exactly what was never discovered. Nevertheless, the testimony heard by the jury over two days in July in a closed Parisian courtroom was enough to convince them that this former exotic dancer, who could count as her lovers a “who’s who” of European men, was, in fact, a spy. She was sentenced to death.

At age 18, the result of a matrimonial advertisement, she married a middle-aged colonial captain in the Dutch army, John Rudolph Campbell MacLeod. He was posted to duty on the island of Java, where his young and beautiful wife, now 21 years old, learned not only the Malay language, but native dances as well. Her Javanese friends named her Mata Hari, meaning “the eye of the dawn.” Upon returning to Holland, Mata Hari secured a separation from her husband and moved to Paris where she enjoyed a life of excess and soon became known as an exotic Hindu dancer. She performed throughout Europe, all the while engaging in liaisons with powerful and wealthy men. In 1914 she moved to Germany, where she is believed to have been trained as a spy in Antwerp.

With World War I on, Mata Hari returned to Paris; she was permitted to enter France since she owned property there and was a citizen of neutral Holland. She renewed her ties with men of influence and in that capacity collected information for the Germans. The Allied nations kept a close eye on her, and, suspecting her of espionage, set a trap for her. She became a double agent. The French sent her to Spain to work, but there she reportedly met regularly with German intelligence agents. When the Germans ordered her back to Paris, Allied officials—having intercepted a German cable for her—awaited her return. They arrested Mata Hari, who was found in possession of a check from the Germans. At her trial, a report compiled by the French and holding Mata Hari responsible for the deaths of some 50,000 Allied soldiers, was brought into evidence. She was killed by firing squad on October 15, 1917, the war still more than a year from ending.