Alexandre Dumas 
The-Man-in-the-Iron-Mask [EPUB ebook] 

The Iron Mask was an individual whose identity has never really been ascertained and which of the historical records say he was a prisoner during the reign of Louis XIV of France. Among the authors who took an interest in his case were Voltaire above all and Alexandre Dumas father, who made him a character in the novel The Viscount of Bragelonne. Numerous films were inspired by that episode of Dumas’ novel, with varying degrees of fidelity. Casanova also mentions the Iron Mask in his biographical work History of my life, in Chapter XXIV, where he affirms that his French teacher, Crébillion, the old man who had been Royal Censor, received from King Louis XIV the confidence that he was not no iron mask ever existed and that it was a legend. It is also said that it was a minister of the Duke of Mantua, named Mattioli, who was simultaneously in the service of Louis XIV and would have betrayed him.