 Marcel Pagnol deduces that in July 1669 King Louis XIV and Louvois, knowing that Eustache Dauger de Cavoye had been interned for approximately one year, gave his name (truncating it) to the man arrested and taken to Calais, who was the prisoner in the iron mask.Marcel Pagnol states that Eustache Dauger de Cavoye died in detention in 1679, without however quoting any document proving this.In the documents at Marcel Pagnol's disposal, the name Eustache Dauger appears for the first time in the letter from Louvois dated 19 July 1669 (i.e.