The Man in the Iron Mask by Alexandre Dumas - was an unidentified prisoner of state, arrested in July 1669 under the pseudonym of "Eustache Dauger" and incarcerated for a period of 34 years during the reign of King Louis XIV of France (1643-1715). Known for remaining unidentified throughout his time in prison, he was held in the custody of the same jailer, Bénigne Dauvergne de Saint-Mars, in four successive French prisons, including the Bastille. When he died there on 19 November 1703, his inhumation certificate bore the pseudonym of "Marchialy".The true identity of this prisoner remains a mystery, even though it has been extensively debated by historians, and various theories have been expounded in numerous books, articles, plays, and films. Among the leading theories is one proposed by the French philosopher and writer Voltaire, who claimed in the second edition of his Questions sur l'Encyclopédie (1771) that the prisoner was an older, illegitimate brother of Louis XIV. This assertion of a royal connection was echoed later by authors who proposed variants of this aristocratic solution.What little is known about the historical prisoner is based on contemporary documents that surfaced during the 19th century, mainly the correspondence between Saint-Mars and his superiors in Paris. Legend has it that no one is known to have seen his face, as it was hidden by a mask of black velvet cloth, later misreported by Voltaire as an iron mask.