Man in the Iron Mask There was also Nicolas Fouquet, Marquis of Belle-Île, a former superintendent of finances who had been jailed by Louis XIV on the charge of embezzlement, and the Marquis de Lauzun, who had become engaged to the Duchess of Montpensier, a cousin of the King, without the King's consent. Fouquet's cell was above that of Lauzun. In his letters to Louvois, Saint-Mars describes Dauger as a quiet man, giving no trouble, "disposed to the will of God and to the king", compared to his other prisoners, who were either always complaining, constantly trying to escape, or simply mad. Dauger was not
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