Pere Papon asserts that a valet who served the masked prisoner died in his master’s room.  Now the man who waited on Fouquet, and who like him was sentenced to lifelong imprisonment, died in February 1680 (see letter of Louvois to Saint-Mars, 12th March 1680).  Echoes of incidents which took place at Pignerol might have reached the Iles Sainte-Marguerite when Saint-Mars transferred his “former prisoner” from one fortress to the other.  The fine clothes and linen, the books, all those luxuries in fact that were lavished on the masked prisoner, were not withheld from Fouquet.  The furniture of a second room at Pignerol cost over 1200 livres (see letters of Louvois, 12th Dec. 1665, and 22nd Feb, 1666).

It is also known that until the year 1680 Saint-Mars had only two important prisoners at Pignerol, Fouquet and Lauzun.  However, his “former prisoner of Pignerol,” according to Du Junca’s diary, must have reached the latter fortress before the end of August 1681, when Saint-Mars went to Exilles as governor.  So that it was in the interval between the 23rd March 1680, the alleged date of Fouquet’s death, and the 1st September 1681, that the Iron Mask appeared at Pignerol, and yet Saint-Mars took only two prisoners to Exilles.  One of these was probably the Man in the Iron Mask; the other, who must have been Matthioli, died before the year 1687, for when Saint-Mars took over the governorship in the month of January of that year of the Iles Sainte-Marguerite he brought only one prisoner thither with him.  “I have taken such good measures to guard my prisoner that I can answer to you for his safety” (’Lettres de Saint-Mars a Louvois’, 20th January 1687).

In the correspondence of Louvois with Saint-Mars we find, it is true, mention of the death of Fouquet on March 23rd, 1680, but in his later correspondence Louvois never says “the late M. Fouquet,” but speaks of him, as usual, as “M.  Fouquet” simply.  Most historians have given as a fact that Fouquet was interred in the same vault as his father in the chapel of Saint-Francois de Sales in the convent church belonging to the Sisters of the Order of the Visitation-Sainte-Marie, founded in the beginning of the seventeenth century by Madame de Chantal.  But proof to the contrary exists; for the subterranean portion of St. Francis’s chapel was closed in 1786, the last person interred there being Adelaide Felicite Brulard, with whom ended the house of Sillery.  The convent was shut up in 1790, and the church given over to the Protestants in 1802; who continued to respect the tombs.  In 1836 the Cathedral chapter of Bourges claimed the remains of one of their archbishops buried there in the time of the Sisters of Sainte-Marie.  On this occasion all the coffins were examined and all the inscriptions carefully copied, but the name of Nicolas Fouquet is absent.

Voltaire says in his ‘Dictionnaire philosophique’, article “Ana,” “It is most remarkable that no one knows where the celebrated Fouquet was buried.”