Man in the Iron Mask

Arrested under the name "Eustache Dauger" near Calais on 28 July 1669, the man was imprisoned for "what he was employed to do" and "what he knew" - labels that explained nothing. He spent 34 years in the custody of Bénigne Dauvergne de Saint-Mars, moved through four prisons including the Bastille, and was made to wear a black velvet mask when travelling between them after 1687. He died on 19 November 1703; his burial certificate gave the name "Marchioly", leading some to believe he was Italian diplomat Ercole Antonio Mattioli. Correspondence uncovered in the 19th century called him "only a valet." Voltaire claimed he was Louis XIV's illegitimate older brother; others said twin, or son of Cromwell, or a duke. In 1932 a historian proposed he was nobleman Eustache Dauger de Cavoye, but family letters disproved it in 1953. Alexandre Dumas made him the king's twin in his 1850 novel. The case remains open.