The Prisoner Who Followed His Jailer's Career

What We Know

His cell was ordered nine days before his arrest was. On 19 July 1669 the war minister, Louvois, wrote to the governor of the fortress prison at Pignerol, a former musketeer named Bénigne Dauvergne de Saint-Mars, with specifications. Windows overlooking nothing a person could get to. Doors enough, closing one upon another, that the sentries would hear nothing. Saint-Mars was to carry the man’s food in himself, once a day, never to listen to anything the prisoner said, and to threaten him with death if he opened his mouth about anything other than his needs. On furniture Louvois was relaxed: as this was “only a valet,” nothing considerable would be required.

The name in that letter is Eustache Dauger. A sealed royal order nine days later sent a sergeant-major from Dunkirk to fetch him; a travel-expense claim later found among Colbert’s papers puts the handover at Calais. He reached Pignerol around 21 August.

Then the name stops. “Eustache” does not appear again in the surviving correspondence for nine and a half years. Roughly a hundred and fifty letters passed between Louvois and Saint-Mars about this prisoner, and in them the jailers call him by working nicknames: the longtime prisoner, the man sergeant Vauroy brought, the one whose name is not said.

He moved when Saint-Mars moved. Pignerol until 1681, then the mountain fort at Exilles when Saint-Mars was made governor there, then the island fortress of Sainte-Marguerite in 1687, then the Bastille in 1698, the post that crowned his career. The Bastille’s lieutenant, Étienne du Junca, logged the arrival in his register: an old prisoner from Pignerol, whom the governor keeps always masked, “whose name is not said.” Du Junca logged the death too, on 19 November 1703. The unknown prisoner, always in a mask of black velvet, had felt slightly unwell coming out of mass the day before.

The Roadblock

The problem is not that the paperwork is missing. It survives, in quantity, and it is useless. Louvois and Saint-Mars were each writing to a man who needed no explanation, so neither ever wrote one down. Across those letters they handle his cell, his food, his health and his security, and never once his identity or his offence.

What he might have left behind was destroyed on purpose. After the death, Bastille staff pulled apart the walls and floors of his cell looking for anything he had written, burned his belongings, then scraped and whitewashed the room.

The chain of custody has a fork in it. At Exilles, Saint-Mars was holding two nameless prisoners, and one of them died in January 1687. The standard reading is that the man who died was La Rivière, once Fouquet’s valet, and that Dauger went on to the island. The letters name neither.

And the field inherited its questions from a writer of entertainments. Voltaire published the story in 1751, dated the arrest to 1661, and put the man at Sainte-Marguerite first. The archive contradicts both. Everyone since has been arguing about a different prisoner: arrested eight years later, at Pignerol.

Best Guesses

A Valet Who Saw the England Papers

Nothing in the surviving letters says what the prisoner knew. That objection has always dogged the reading Jean-Christian Petitfils published in 2003, the standard French account. The man was a servant, whose name Petitfils reads as Danger, and during the secret talks then running between Louis XIV and Charles II he handled papers he was not meant to see. Reviewing the book, the historian Diego Venturino accepted the identification and named that limit: the identity is unveiled, the reason for the imprisonment is not. What holds the reading up is the security itself, obsessive about communication and indifferent to rank.

A Valet Who Knew Mazarin’s Accounts

Paul Sonnino spent decades in the French archives, and came out in 2016 with something more specific: Dauger was a valet to Antoine-Hercule Picon, an intimate of Colbert’s, and what he knew was where Cardinal Mazarin’s fortune had come from, some of it squeezed out of the English royal family, at the moment Louis XIV was trying to talk their son, Charles II, into a war. Writing in French History, David Parrott called the reconstruction highly plausible, then said where it fails: the Picon connection rests on a balance of probabilities rather than written evidence.

Louis XIV’s Half-Brother

Christophe Roustan Delatour, deputy director of the Cannes museums, argues that the prisoner was Eustache Dauger de Cavoye and that his mother was Anne of Austria: a half-brother whose existence was an embarrassment to the succession, held for what he was rather than for anything he knew. The royal readings got support in 2016, when Sarah Madry argued in a scholarly journal that Louvois’s word “valet” cannot carry the weight historians hang on it. The wound is documentary. A real Eustache d’Auger de Cavoye was locked up at Saint-Lazare in Paris, and wrote to his sister in 1678 complaining of ten years there. The masked man was in the Alps.

A Nobody His Jailer Made Famous

Louvois’s orders concern speech, never the face. John Noone’s 1988 reading builds on that: the man was ordinary, and the secrecy was Saint-Mars’s own work. No mask appears anywhere in the record for the first eighteen years — it surfaces in 1687, in handwritten news-sheets, during a transfer Saint-Mars was stage-managing. Petitfils, who disagrees with Noone about nearly everything else, agrees on that much: Saint-Mars dressed an ordinary detainee up as a great personage. But Saint-Mars did not write the sealed order, and he did not pay the bills. Versailles did, for thirty-four years.

No Name Was Ever Written Down

The last position is that there is nothing to find. The name disappears from the correspondence within days of the arrest order and almost never returns. The Bastille’s register carries a burial name its own author admitted he picked up secondhand, afterwards. The Saint-Paul parish register, the single document that held that name in an original hand, burned along with nearly every parish register in Paris in 1871. The counter-argument is small but real: Stanislas Brugnon found the 1669 travel-expense order in Colbert’s papers in the 1980s. Oblique documents still turn up.

The Verdict

Saint-Mars wrote to a patron in June 1681 about his new governorship at Exilles. He led with the money, two thousand livres, mentioned in passing that he would be bringing two blackbirds, as he called them, who had no other names than the gentlemen of the lower tower, and then listed what two colleagues had been given for their posts. That is the register the whole case survives in: a careerist’s correspondence, where the most famous prisoner in French history is a line item between salaries.

The gap is a name, and the war-ministry correspondence will not produce it; nothing is left in it. Anything that still could is duller paper: a paymaster’s ledger, or a clerk’s duplicate filed where nobody thought to be careful. Louvois wrote to be understood by one man. The bureaucracy underneath him wrote to be audited.

The man who kept the Bastille’s book learned the burial name afterwards, secondhand, and never wrote down who told him. Nobody has done better since.