Lamotte-Guérin, who therefore had access to the prison records, gives the date of the prisoner's arrest (1669). He spends time with the prisoner every day, for example when he accompanies Saint-Mars to serve the prisoner's meals, as Saint-Mars describes in a letter to Louvois in January 1696. Thirty years before the publication of Voltaire's "The Age of Louis XIV", Lagrange-Chancel already refers to the consideration shown by Saint-Mars, the silver dishes and luxury clothes. The prisoner is identified as the Duke of Beaufort, who died at the Siege of Candia.