In the spring of 1598, King Henry IV of France signed the landmark Edict of Nantes, bringing decades of bloody civil war between French Catholics and Protestant Huguenots to a fragile, exhausted truce. Barely months later, that hard-won religious peace was nearly blown apart—not by an invading Spanish army, but by a twenty-two-year-old weaver’s daughter from the Loire Valley named Marthe Brossier. Travelling from parish to parish barking, speaking in tongues, and contorting her body while claiming to be possessed by the devil Beelzebub himself, Brossier became a weapon of anti-Huguenot street propaganda until a team of skeptical Parisian physicians subjected her “demon” to one of the earliest controlled clinical blind tests in medical history.
A Bankrupt Weaver’s Daughter and the Demon Beelzebub
Born around 1576 in the small town of Romorantin in central France, Marthe Brossier was the third daughter of Jacques Brossier, a once-prosperous cloth merchant whose business had fallen into debt during the French Wars of Religion. Unmarried at twenty-two and having expressed an erratic desire to cut off her hair and dress as a boy to enter a monastery, Marthe suddenly began suffering violent physical seizures in early 1598, rolling her eyes back into her head, sticking out her tongue, and roaring in a deep voice.
After initially blaming a neighbor woman for casting a spell on her, Marthe announced a far more sensational diagnosis: her body was inhabited by three distinct demons—led by Beelzebub—who spoke through her mouth to deliver urgent theological messages to the people of France. Conveniently for ultra-hardline Catholic preachers who hated King Henry IV’s new peace treaty with the Protestants, Marthe’s demon shouted during public exorcisms that the Huguenots all belonged to Satan and that tolerating Protestants in France was a mortal sin.
Traveling Roadshow and Panic in Paris (1599)
Recognizing both a lucrative income stream from sympathetic alms-givers and a powerful propaganda spectacle, Jacques Brossier loaded his daughter Marthe and her sisters into a wagon and hit the road across the Loire Valley for over a year. Stopping at Orléans, Angers, and Cléry before arriving in Paris in the spring of 1599, the family staged public exorcisms inside packed churches, most notably the Abbey of Sainte-Geneviève.
Hosted by zealous Capuchin friars who genuinely believed—or politically exploited—her condition, Marthe put on an astonishing athletic performance on the church floor:
- While lying flat on her back, she vaulted four feet straight into the air like a landed trout without visibly using her hands or knees.
- When priests pricked her neck and hands with long sewing needles during her trance, she neither flinched nor bled a single drop.
- Whenever a friar sprinkled a drop of holy water on her skin or read a passage from the Latin exorcism ritual, she writhed in agony; yet when she was asked questions in ancient Greek or English, her “demon” remained suspiciously silent or answered in basic French.
Dr. Michel Marescot’s Double-Blind Clinical Test
Watching huge, angry crowds gather outside Parisian churches after watching Marthe’s anti-Protestant exorcisms, King Henry IV—himself a former Protestant who had converted to Catholicism to secure the throne—realized that if he arrested her by brute military force, the public would hail her as a martyr; if he let her continue, a riot would shatter the Edict of Nantes. So the Bishop of Paris and the King appointed a blue-ribbon panel of France’s finest royal physicians, led by Dr. Michel Marescot, to examine Marthe Brossier scientifically over forty days.
Instead of arguing theology with the Capuchins, Dr. Marescot and previously skeptical churchmen in Orléans and Angers subjected Marthe’s “demon” to a brilliant series of empirical **placebo and blind tests**:
- The Fake Holy Water Switch: According to canon law, a demon recoils in terror at the touch of consecrated holy water, and ignores ordinary tap water. Without telling Marthe, doctors filled an ornate silver church holy-water vessel with plain kitchen tap water and sprinkled her: instantly, Marthe threw herself onto the floor in violent “demonic” convulsions! Ten minutes later, they brought her a plain kitchen cup filled with genuine consecrated holy water to drink—and she gulped it down calmly without a single twitch.
- Virgil’s Aeneid Disguised as an Exorcism Book: Knowing that Marthe knew only a few common words of church Latin, a priest solemnly stepped before her holding a thick, leather-bound volume bound like a liturgical missal. Chanting in a booming, priestly exorcism cadence, he began reading aloud—not from the Bible, but from the opening lines of the pagan Roman poet Virgil’s Aeneid (Arma virumque cano…) and passages from Cicero! Hearing the solemn Latin rhythm and thinking she was being exorcised, Marthe immediately collapsed into a wild demonic fit over a harmless Roman history poem.
The Verdict of Marescot and the Papal Finale
In late May 1599, Dr. Michel Marescot published his landmark medical report, summarizing forty days of observation in one immortal, devastating Latin sentence that became a motto of the Scientific Revolution: “Nihil a demone; multa ficta; pauca a morbo”—”Nothing from the Devil; much that is faked; a little from illness.”
The Parlement of Paris ordered Jacques and Marthe Brossier escorted back to their hometown of Romorantin under house arrest and banned her from leaving the parish on pain of corporal punishment. Even after an ambitious nobleman, Alexander de La Rochefoucauld, smuggled Marthe out of town in 1600 and drove her all the way to Rome hoping to persuade Pope Clement VIII to validate her possession and embarrass King Henry IV, French Cardinal d’Ossat was waiting for them at the Vatican with copies of Dr. Marescot’s blind-test experiments. Refusing to be duped, the Pope ordered the disgraced priest to apologize to his King and consigned Marthe Brossier to a quiet Roman convent hospital, where her noisy demons vanished forever.