Editing Man in the Iron Mask (section)

====Dauger de Cavoye in prison at Saint-Lazare====
In 1953, however, French historian Georges Mongrédien published historical documents{{efn|name=cavoye}} confirming that, in 1668, Eustache Dauger de Cavoye was already held at the [[Prison Saint-Lazare]] in Paris—an asylum, run by monks, which many families used in order to imprison their "[[black sheep#Idiomatic usage|black sheep]]"—and that he was still there in 1680,{{sfn|Mongrédien|1961|p=220}} at the same time that "Eustache Dauger", was in custody in Pignerol, hundreds of miles away in the south. These documents include a letter dated 20 June 1678, full of self-pity, sent by Dauger de Cavoye to his sister, the Marquise de Fabrègues,{{efn|name=sarret}} in which he complains about his treatment in prison, where he had already been held "for more than 10 years", and how he was deceived by their brother Louis and by Clérac, their brother-in-law and the manager of Louis's estate.{{sfn|Mongrédien|1953|pp=56–57}}

Dauger de Cavoye also wrote a second letter, this time to the King but undated, outlining the same complaints and requesting his freedom.{{sfn|Mongrédien|1953|pp=57–58}} The best the King would do, however, was to send a letter to the head of Saint-Lazare on 17 August 1678,{{efn|name=stlazare}} telling him that "M. de Cavoye should have communication with no one at all, not even with his sister, unless in your presence or in the presence of one of the priests of the mission". The letter was signed by the King and Colbert.{{sfn|Noone|1988|pp=231–234}} A poem written by Louis-Henri de Loménie de Brienne, an inmate in Saint-Lazare at the time, indicates that Eustache Dauger de Cavoye died as a result of heavy drinking in the late 1680s. Historians consider all this proof enough that he was not involved in any way with the man in the mask.{{sfn|Noone|1988|p=233}}{{sfn|Lincoln ''Timewatch'', 1988}}