We come at last to the hypothesis which is the most probable of all--after the true hypothesis, of course. Eustache Dauger, whom M. Lair identifies with the masked prisoner, was a valet, who had been put into jail at Pignerol on July 28, 1669. But it must be noted that the masked prisoner was kept guarded in rigorous secrecy in the early days of his detention, as long as he was at Pignerol and the Isles of Sainte-Marguerite. Now, when Dauger went to Pignerol, his case seemed of such slight importance that Saint-Mars thought of making him into a servant for the other prisoners, and in fact, in 1675, Louvois gave him as a valet to Fouquet, who for some time past had seen the rigour of his confinement sensibly mitigated, receiving visits, walking freely in the courts and purlieus of the fortress, Dauger accompanying him. Further, we know that the masked man was transferred direct from Pignerol to the Isles of Sainte-Marguerite, whilst Dauger was transferred in 1681 to Exiles, whence he only went to the Isles in 1687. We now come to the correct solution. 3. MATTIOLI. To Baron Heiss, once captain in the Alsace regiment, and one of the most distinguished bibliophiles of his time, belongs the honour of being the first, in a letter dated from Phalsbourg, June 28, 1770, and published by the _Journal encyclopédique_, to identify the masked prisoner with Count Mattioli, secretary of state to the Duke of Mantua. After him, Dutens, in 1783, in his _Intercepted Correspondence_; Baron de Chambrier, in 1795, in a Memoir presented to the Academy of Berlin; Roux-Fazillac, member of the Legislative Assembly and the Convention, in a remarkable work printed in 1801; then successively, Reth, Delort, Ellis, Carlo Botta, Armand Baschet, Marius Topin, Paul de Saint-Victor, and M. Gallien, in a series of publications more or less important, endeavoured to prove that the Man in the Mask was the Duke of Mantua's secretary of state. The scholars most intimate with the history of Louis XIV.'s government, Depping, Chéruel, Camille Rousset, have not hesitated to pronounce in favour of the same view; while against them, singlehanded like his D'Artagnan, Alexandre Dumas resisted the efforts of twenty scholars, and the _Vicomte de Bragelonne_--giving a new lease of life to the legend about the brother of Louis XIV., put in circulation by Voltaire, and reinforced by the Revolution--drove back into their dust among the archives the documents which students had exhumed. We have no longer to deal with so formidable an adversary, and we hope that the following pages will not leave the shadow of a doubt.