Man in the Iron Mask in the mask. It has even been suggested that he was one of the other famous contemporary prisoners being held at Pignerol at the same time as Dauger. Voltaire claimed that the prisoner was a son of Anne of Austria and Cardinal Mazarin, and therefore an illegitimate half-brother of King Louis XIV. However, the sincerity of this claim is uncertain. In his history essay "Le Masque de fer", French novelist Marcel Pagnol, supporting his theory in particular on the circumstances of King Louis XIV's birth, claims that the Man in the Iron mask was indeed a twin but born second,
Man in the Iron Mask suggested that Dauger may have poisoned Fouquet as part of a complex power struggle between Louvois and his rival Colbert. However, evidence has emerged that Dauger de Cavoye actually died in the Prison Saint-Lazare, an asylum run by monks which many families used in order to imprison their "black sheep". Documents have survived indicating that Dauger de Cavoye was held at Saint-Lazare in Paris at about the same time that Dauger, the man in the mask, was taken into custody in Pignerol, hundreds of miles away in the south. These include a letter sent to Dauger de Cavoye's sister, the