The Man in the Iron Mask
How a complete unknown became France’s most famous prisoner
In mid-November 1703 (the exact date is debated), a prisoner died in the Bastille. The man listed only as “Marchioly” at burial had spent his final years in a cell furnished only with a sleeping mat, a solitary figure whose death and burial never even made the newspapers.
By mid-century, all of France would be wondering who he was.
The original silence (1703-1710)
Historians largely agree on the broad facts. A masked prisoner arrived at the Bastille in 1698 from the Mediterranean fortress of Sainte-Marguerite, just off the coast of Cannes.
His jailer, Bénigne Dauvergne de Saint-Mars, had guarded him for years, moving him through a succession of French prisons each time he took up a new posting. Following your jailer was an unusual arrangement, suggesting that the prisoner’s identity was so sensitive only his jailer could be trusted with it.
The convict, who was incarcerated for a total of 34 years, had been sent to jail by Louis XIV, without any announcement or fanfare. When he arrived at the Bastille, Lieutenant Étienne Du Junca – who kept the official prison register – recorded only that Saint-Mars "brought with him a prisoner he had formerly at Pignerol, whom he keeps always masked, whose name is not spoken." When the prisoner died five years later, Du Junca noted his burial under the name "Marchioly" with no further details. It was a well-kept secret that was supposed to have stayed that way.
The first whispers (1710s-1740s)
The secret became less secret around 1711 when an unexpected source, the Princess Palatine (Louis XIV’s outspoken sister-in-law) wrote about rumors concerning a masked prisoner, someone who “resembled” someone important. Aristocratic circles went breathless with curiosity.
After Louis’s death in 1715, all sorts of revelations began to surface, about his morganatic wife Madame de Maintenon, about his treatment of Protestant relatives, about his personal intrigues… his secrets were seeping out. The sudden “revelation” of a mysterious masked stranger made perfect sense for those times.
Over the decades, the whispers grew, and the masked prisoner became a fashionable topic of conversation in the salons of Paris. His hidden identity captured imaginations, and since no one can resist repeating a good secret, the rumor spread.
And then Voltaire took up his pen.
Voltaire creates a myth (1751)
In Le Siècle de Louis XIV (The Century of Louis XIV) published in 1751, Voltaire made an explosive claim: the prisoner was none other than Louis XIV’s older brother, a secret twin who threatened the succession. Voltaire provided specific “details”: the prisoner was “young and dark,” of “extraordinary height,” was treated with deep respect but never allowed to show his face.
Where did Voltaire get this information? In fact, he was imprisoned in the Bastille twice, once from 1717-1718 and briefly in 1726 – all well and good but a little late for any first-hand accounts.
He claimed to have spoken to men who had served the prisoner, but this is a little hard to believe: custodians who had any personal contact with the masked man had died before Voltaire ever set foot in the prison. At best, he relied on secondhand accounts and circles close to the Bastille: figures such as Jean Marsolan, a surgeon whose father-in-law (the physician Fresquière) was said to have attended the prisoner; Charles de Fournier de Bernaville, governor of the Bastille from 1708 to 1718; and Louis d’Aubuisson, duc de La Feuillade, whose family connections reached into the highest levels of Louis XIV’s administration.
But Voltaire was less concerned about facts than about telling a brilliant story which provided a teachable moment. The theory of the twins was perfect for his Enlightenment ideals: it showed how cruel absolute monarchs could be, and how far they’d go to protect their power.
The version of the story involving a royal twin also conveniently explained everything – the mask (so he couldn’t be recognized), the good treatment (he must have been of royal blood), the absolute secrecy (threat to legitimacy), and the lifetime imprisonment (too dangerous to kill, too dangerous to free).
The Revolution adds fuel to the fire (1789-1799)
When Parisian crowds stormed the Bastille on 14 July 1789, they searched in earnest for the man in the iron mask. By now, everyone “knew” a great victim of royal tyranny had been imprisoned there. But the mob found only seven prisoners and a room full of carefully maintained archives that included documents from as early as 1659. Sadly for history, the revolutionaries spent two days ransacking and burning everything, tearing papers and throwing them from the towers into the moats. Some were also stolen by eagle-eyed collectors, writers, lawyers, even a Russian embassy attaché who later sold them.
Then revolutionary pamphleteers got hold of the story. The masked prisoner (however impossible to find) became the cause célèbre of monarchical evil, an innocent victim of royal paranoia. Since nothing was known, everything could be claimed or retold. The masked man could be anyone – he could be the true king, a legitimate prince, a Protestant noble, a too-honest minister… It was even said that revolutionaries exploring the prison’s depths had discovered a skeleton still wearing a metal mask, a total fabrication that served revolutionary propaganda perfectly.
The Revolutionary government ordered an investigation. Officials searched what little remained of the archives, and interviewed elderly Parisians who might remember stories. They found Du Junca’s register entries for the prisoner’s arrival and death but nothing about who Marchioly was or why he’d been masked.
The story became quasi immortal, precisely because the investigation failed. In this way, the mystery would continue to exist. And if even revolutionary investigators with access to royal archives couldn’t solve it, then it must be a profound mystery indeed. More fuel for the fire.
Dumas makes it immortal (1847-1850)
Decades later, the writer Alexandre Dumas would take a conspiracy theory and turn it into a full romantic legend. In The Vicomte de Bragelonne (serialized from October 1847 to January 1850), he “borrowed” Voltaire’s twins and added a swashbuckling adventure. His prisoner wasn’t just a threat to the throne – he was a noble innocent, betrayed by his own brother.
The novel’s massive length (the edition on my bookshelf runs six volumes) initially intimidated readers, but Dumas’s pen was genius: he made his prisoner suffer beautifully, and so the audience wept for him. Rather than a dry story about constitutions and dynasties, it morphed into a tale of sacrifice and injustice.
By 1850, the real prisoner – whoever he was – had been utterly eclipsed by the literary one. Dumas’s version would eventually be translated into nearly 100 languages and made into countless films, and the iron mask (probably velvet, actually) became an instantly recognizable symbol.
Historians fight back (1890s-present)
As professional historiography developed in the late 19th century, scholars tried to reclaim the story from fiction. They examined the archives systematically, and two candidates for the prisoner emerged as most plausible.
The masked prisoner’s actual existence had already been confirmed in 1769 when Jesuit Father Henri Griffet published excerpts from Du Junca’s official Bastille register in his book on historical evidence. What had not been resolved was his identity.
Eustache Dauger remains the most accepted candidate for the role of Iron Mask. A valet arrested in 1669, his name appears in ministerial correspondence at the time of Louis XIV. Letters show Dauger was picked up near Dunkirk and imprisoned at Pignerol in August of that year. He had served Nicolas Fouquet (the disgraced finance minister) as a valet in prison, was kept in extraordinary secrecy, and moved with Saint-Mars to every prison posting, matching the masked prisoner’s timeline more closely than any other. But the mystery remained: why would a mere valet require such extreme measures? Letters from the war ministry suggested Dauger knew something dangerous, possibly involving state finance or court scandals.
Count Ercole Antonio Mattioli was another favorite among many 19th-century historians. The Italian diplomat betrayed Louis XIV in a secret treaty negotiation concerning a fortress, and Louis, furious, had him kidnapped and imprisoned at Pignerol in 1679. His surname isn’t dissimilar to the “Marchioly” of the burial certificate. However, most historians now believe Mattioli died in 1694, nine years before the masked man’s recorded death in 1703.
Other candidates proposed over the years include a son of Louis XIV and his mistress Louise de la Vallière, a bastard son of Charles II of England, Nicolas Fouquet’s son, Fouquet himself, or the Duke of Monmouth, to name a few of the more than 50 contenders for the role of Mr Iron Mask. Each theory has problems when it comes to evidence: there were huge gaps in records, correspondence often used code names, prison records were incomplete, and the prisoner’s own possessions were burned, making it impossible to glean anything personal from them.
So… why this prisoner?
The Bastille held thousands of prisoners during in its four centuries of existence, many of them housed here for decades, in secret. Some were political prisoners of higher rank than Dauger. Yet only one became a legend.
This may have had something to do with timing, since the masked prisoner’s story surfaced precisely when France needed it.
This is a story of a prisoner who became famous not because he was known, but precisely because he was not, allowing everyone to project their own imagination onto him – Voltaire needed a victim of royal tyranny, the Revolution needed a martyr, Dumas needed a tragic hero, and even modern conspiracy theorists need an unsolved mystery, one still being explored today.
From the travel blog
A Day in the Life of Louis XIV, Sun King
Voltaire in Love: The Improbable Power Couple of the Chateau de Cirey
If you’re planning a trip to France, visit my travel blog at OffbeatFrance.com and explore France’s lesser known corners – without skipping the places you’ve always dreamed of seeing, of course. Practical, curious, and a little unexpected.
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Resources
Josephine Wilkinson, The Man in the Iron Mask: The True Story of Europe’s Most Famous Prisoner (Pegasus Books, 2021).
Paul Sonnino, The Search for the Man in the Iron Mask: A Historical Detective Story (Rowman & Littlefield, 2016).
Alexandre Dumas, The Vicomte de Bragelonne: Ten Years Later, trans. Lawrence Ellsworth (Pegasus Books, 2020). Also available on Project Gutenberg.
“Man in the Iron Mask,” Wikipedia, last modified November 25, 2025.
Josephine Wilkinson, “How Voltaire Helped Spread the Legend of Europe’s Most Famous Prisoner, The Man in the Iron Mask,” CrimeReads, July 7, 2021.
Erin Blakemore, “Who Was the Real Prisoner Behind Dumas’s Man in the Iron Mask?,” National Geographic, September 8, 2025,
Frantz Funck-Brentano, “Chapter IV: The Man With the Iron Mask,” from Legends of the Bastille, translated by George Maidment, Elfinspell,
Very entertaining and informative read, thank you. We visited Sainte-Marguerite not too long ago and saw the cell where he was held. The view from the cell through the iron bars was amazing, and it had to be heartbreaking to be cut off from such beauty.
I saved this for a slow read and definitely learned a lot. To be honest, I thought the man was a fictional character and knew nothing of the historical background. I'm curious how long it takes you to put together an article like this.