Man in the Iron Mask Dumas also presented a review of the popular theories about the prisoner extant in his time in the chapter "L'homme au masque de fer" in the sixth volume of his non-fiction "Crimes Célèbres". The earliest surviving records of the masked prisoner are from late July 1669, when Louis XIV's minister, the Marquis de Louvois, sent a letter to Bénigne Dauvergne de Saint-Mars, governor of the prison of Pignerol, which at the time was part of France. In his letter, Louvois informed Saint-Mars that a prisoner named "Eustache Dauger" was due to arrive in the next month or so. Louvois instructed
Man in the Iron Mask appointed governor of the prison of the Exiles Fort (now Exilles in Italy). He went there, taking Dauger and La Rivière with him. La Rivière's death was reported in January 1687; in May, Saint-Mars and Dauger moved to Sainte-Marguerite, one of the Lérins Islands, half a mile offshore from Cannes. It was during the journey to Sainte-Marguerite that rumours spread that the prisoner was wearing an iron mask. Again, he was placed in a cell with multiple doors. On 18 September 1698, Saint-Mars took up his new post as governor of the Bastille prison in Paris, bringing Dauger with him.