In 1802 an octavo pamphlet containing 11 pages, of which the author was perhaps Baron Lerviere, but which was signed Reth, was published.  It took the form of a letter to General Jourdan, and was dated from Turin, and gave many details about Matthioli and his family.  It was entitled ‘Veritable Clef de l’Histoire de l’Homme au Masque de Fer’.  It proved that the secretary of the Duke of Mantua was carried off, masked, and imprisoned, by order of Louis xiv in 1679, but it did not succeed in establishing as an undoubted fact that the secretary and the Man in the Iron Mask were one and the same person.

It may be remembered that M. Crawfurd writing in 1798 had said in his ‘Histoire de la Bastille’ (8vo, 474 pages), “I cannot doubt that the Man in the Iron Mask was the son of Anne of Austria, but am unable to decide whether he was a twin-brother of Louis xiv or was born while the king and queen lived apart, or during her widowhood.”  M. Crawfurd, in his ‘Melanges d’Histoire et de Litterature tires dun Portefeuille’ (quarto 1809, octavo 1817), demolished the theory advanced by Roux-Fazillac.

In 1825, M. Delort discovered in the archives several letters relating to Matthioli, and published his Histoire de l’Homme au Masque de Fer (8vo).  This work was translated into English by George Agar-Ellis, and retranslated into French in 1830, under the title ’Histoire authentique du Prisonnier d’Etat, connu sons le Nom de Masque de Fer’.  It is in this work that the suggestion is made that the captive was the second son of Oliver Cromwell.

In 1826, M. de Taules wrote that, in his opinion, the masked prisoner was none other than the Armenian Patriarch.  But six years later the great success of my drama at the Odeon converted nearly everyone to the version of which Soulavie was the chief exponent.  The bibliophile Jacob is mistaken in asserting that I followed a tradition preserved in the family of the Duc de Choiseul; M. le Duc de Bassano sent me a copy made under his personal supervision of a document drawn up for Napoleon, containing the results of some researches made by his orders on the subject of the Man in the Iron Mask.  The original Ms., as well as that of the Memoires du Duc de Richelieu, were, the duke told me, kept at the Foreign Office.  In 1834 the journal of the Institut historique published a letter from M. Auguste Billiard, who stated that he had also made a copy of this document for the late Comte de Montalivet, Home Secretary under the Empire.

M. Dufey (de l’Yonne) gave his ‘Histoire de la Bastille’ to the world in the same year, and was inclined to believe that the prisoner was a son of Buckingham.

Besides the many important personages on whom the famous mask had been placed, there was one whom everyone had forgotten, although his name had been put forward by the minister Chamillart:  this was the celebrated Superintendent of Finance, Nicolas Fouquet.  In 1837, Jacob, armed with documents and extracts, once more occupied himself with this Chinese puzzle on which so much ingenuity had been lavished, but of which no one had as yet got all the pieces into their places.  Let us see if he succeeded better than his forerunners.