Brigadier-General (afterwards the famous Marshal) Catinat reports from Pignerol on May 3rd, 1679:--"I arrested Mattioli yesterday, three miles from here, upon the King's territories, during the interview which the Abbe d'Estrades had ingeniously contrived between himself, Mattioli and me, to facilitate the scheme. For the arrest, I employed only the Chevaliers de Saint Martin and de Villebois, two officers under M. de Saint Mars, and four men of his company. It was effected without the least violence, and no one knows the rogue's name, not even the officers who assisted." This fixed beyond all doubt the identity, but there is a corroborative evidence in a pamphlet still in existence, dated 1682, which states that "the Secretary was surrounded by ten or twelve horsemen who seized him, disguised him, masked him and conducted him to Pignerol." This is farther borne out by a traditionary arrest about that time.
When, thirty years later, the great sensation was first invented, its importance was emphasised by Voltaire and others who declared that at the period of the arrest no disappearance of any important person was recorded. Certainly Mattioli's disappearance was not much noticed. It was given out that he was dead, the last news of him being a letter to his father in Padua begging him to hand over his papers to a French agent. They were concealed in a hole in the wall in one of the rooms in his father's house, and when obtained without demur were forwarded to the King in Paris. There was no longer any doubt of Mattioli's guilt, and Louis exacted the fullest penalty. He would annihilate him, sweep him out of existence, condemn him to a living death as effective as though he were poisoned, strangled or otherwise removed. He did not mean that the man who had flouted and deceived him should be in a position to glory over the affront he had put upon the proudest king in Christendom.
Exit Mattioli. Enter the "Man with the Iron Mask." Pignerol, the prison to which he was consigned, has already been described, and also Saint Mars, his gaoler. The mask was not regularly used at first, but the name of Mattioli was changed on reception to Lestang. We come at once upon evidence that this was no distinguished and favored prisoner. The deference shown him, the silver plate, the fine clothes are fictions destroyed by a letter written by Louvois within a fortnight of the arrest. "It is not the King's intention," he writes, "that the Sieur de Lestang should be well treated, or that, except the necessaries of life, you should give him anything to soften his captivity.... You must keep Lestang in the rigorous confinement I enjoined in my previous letters."