Where Voltaire, Alexandre Dumas, and the team behind 1998's The Man in the Iron Mask failed, Paul Sonnino says he has succeeded. The history professor at UC Santa Barbara claims to have uncovered the true identity of the masked man who, starting in 1669, spent more than 30 years imprisoned in France's Bastille and other jails, Live Science reports. More importantly, Sonnino's new book, The Search for the Man in the Iron Mask: A Historical Detective Story, proposes a theory for why the mystery man was incarcerated in the first place. Sonnino tells the UC Santa Barbara Current that historians already largely agreed that the man's name was Eustache Dauger, and that he was a valet, rather than the twin of King Louis XIV, as Voltaire and Dumas claimed (and the mask, worn only occasionally, was velvet, not iron). But the trail went cold after that.
After researching the case for nearly as long as the man in the iron mask was locked up (he died in 1703), Sonnino has determined that Dauger was the valet to Cardinal Mazarin, chief minister to the French king in the mid-17th century. "Mazarin had ripped off some of his huge fortune from the previous king and queen of England," Sonnino tells the Current. Some of those ill-gotten gains went to the French king. "Eustache was arrested years later just as Louis XIV was trying to con their son, the present king of England, into joining him in a war. Dauger must have blabbed at the wrong time," he says, adding that Dauger was arrested and told to hide his identity or face death. In hiding that identity, Publishers Weekly notes that Dauger's "identity [was] scrubbed from documents," and that he "retains some of his mystery because of a dearth of surviving personal information." (Another mystery solved? "One of the most important shipwrecks" may have been found.)