In July 1518, a woman named Frau Troffea stepped into the narrow streets of Strasbourg and began to dance. She danced without music, without pause, without reason. Within a week, 34 others had joined her. By the end of the month, 400 people were dancing uncontrollably through the streets—and they couldn’t stop. Some danced for days without rest until they collapsed from exhaustion, stroke, or heart attack. This was not celebration. This was terror. And to this day, no one can fully explain what caused the Dancing Plague of 1518.
The First Dancer
It began on a hot summer day in mid-July 1518, in the free imperial city of Strasbourg, then part of the Holy Roman Empire (now in modern-day France). Frau Troffea, whose first name has been lost to history, suddenly stepped into the street near her home and began to dance.
She danced alone, without music, her movements frantic and seemingly involuntary. Neighbors watched in confusion as she continued for hours without stopping. When night fell, she was still dancing. By the next morning, she had danced through the entire night.
Her feet bled. Her body trembled with exhaustion. Yet she could not stop. Days passed, and Frau Troffea continued her relentless, compulsive dancing. Contemporary chronicles record that she danced for between four and six days straight before others began to join her.
What started as a curious spectacle was about to become a nightmare that would grip the city for months.
The Contagion Spreads
Within a week, 34 people had joined Frau Troffea in her manic dance. By the end of August, the number had swelled to approximately 400 dancers. They moved through the streets in a grotesque choreography of suffering—men, women, and children writhing, leaping, and thrashing uncontrollably.
This was not joyful dancing. Witnesses described expressions of anguish and terror on the dancers’ faces. Many screamed and cried as they moved, begging for help, pleading for it to stop. Their feet became bloody and raw. Some dancers were restrained by family members, only to break free and return to dancing the moment they were released.
The historical records from multiple contemporary sources are consistent and disturbing. Physician and diarist Paracelsus, though not present, later wrote about the event based on eyewitness accounts. The city’s official records document the phenomenon in detail. Chronicle writer Sebastian Brant described the dancing plague in vivid terms.
Most chilling of all: people were dying. The exact death toll is debated by historians, but contemporary sources suggest that at the peak of the epidemic, as many as 15 people per day were dying from strokes, heart attacks, and sheer exhaustion. Their bodies simply gave out under the relentless physical demand of dancing for days without rest.
The Authorities Respond
The city authorities faced a crisis unlike anything in living memory. Initially, they consulted with physicians, who approached the problem from the medical understanding of the time.
The prevailing medical theory in 16th-century Europe was based on the concept of the four humors—blood, phlegm, yellow bile, and black bile. Physicians theorized that the dancing was caused by “hot blood” that had overheated the dancers’ brains, driving them to this manic behavior.
The prescribed cure was startling: more dancing. The logic, according to the physicians of the time, was that the only way to cure the affliction was to let the dancers dance it out of their systems. The fever must burn itself out.
The city authorities, following this medical advice, took an extraordinary step: they built special stages and hired musicians to play constantly, encouraging the afflicted to keep dancing. They opened guildhalls and cleared spaces specifically for the dancers. Professional dancers were even brought in to help.
This decision would prove catastrophic. Rather than curing the affliction, it seemed to make it worse. More people began dancing. The phenomenon spread further. The city descended into chaos as hundreds writhed in the streets and public spaces, unable to stop, many dying where they danced.
The musicians played their instruments until their hands bled. The drums beat constantly. And still, the dancers could not stop.
A City in Crisis
Contemporary accounts paint a picture of a city in the grip of genuine terror. Strasbourg in 1518 was a prosperous city of about 20,000 people, a center of trade and commerce. But the dancing plague brought normal life to a standstill.
Families watched helplessly as loved ones danced themselves into oblivion. Children were lost in the crowds of dancers. The elderly collapsed and died in the streets. The sound of drums and desperate cries echoed through the city day and night.
The economic impact was severe. Businesses closed. Markets shut down. Normal commerce became impossible as the streets filled with uncontrollable dancers. The city’s resources were stretched to breaking as they tried to manage the crisis—providing water to the dancers, carrying away the dead, attempting to restrain those who seemed most likely to die from exhaustion.
Religious authorities began to suspect a different cause than “hot blood.” Perhaps this was not a medical condition at all, but a curse—or divine punishment.
The Supernatural Explanation
As the crisis deepened, city authorities abandoned the medical approach and turned to religious intervention. The dancing, they concluded, was a curse brought upon them by Saint Vitus, a Catholic saint associated with epilepsy, dancing mania, and nervous disorders.
According to medieval belief, Saint Vitus could inflict a “dancing curse” upon those who angered him or upon cities that had fallen into sin. The authorities decided that Strasbourg had somehow earned the saint’s wrath, and only divine intervention could end the plague.
They banned all music and dancing, reversing their earlier policy entirely. The stages were dismantled. The musicians were sent away. The silence that fell over the city must have been eerie after weeks of constant drumming.
The afflicted were taken—many forcibly—to the chapel of Saint Vitus at a nearby shrine in Saverne, about 25 miles from Strasbourg. There, they were encouraged to pray for forgiveness and intercession. Some were made to wear red shoes blessed by priests. Others were given small carved images of Saint Vitus to hold.
And then, gradually, mysteriously, the dancing began to stop.
By early September 1518—approximately two months after Frau Troffea first began dancing—the plague had ended as suddenly and inexplicably as it had begun. The dancers stopped. Those who had survived slowly recovered. The city began to return to normal life, though haunted by the memory of what had occurred.
Modern Medical Explanations
For centuries, the Dancing Plague of 1518 was dismissed as legend or exaggeration. But the historical documentation is too extensive and too consistent to dismiss. Multiple independent sources confirm the basic facts: in the summer of 1518, hundreds of people in Strasbourg danced uncontrollably for weeks, and many died.
Modern researchers have proposed several theories to explain this bizarre event:
Ergot Poisoning: Some researchers initially suggested that the dancers might have consumed bread made from rye grain contaminated with ergot, a fungus that contains compounds similar to LSD. Ergot poisoning (known as “St. Anthony’s Fire”) can cause hallucinations, convulsions, and involuntary movements.
However, most historians now reject this theory. Ergot poisoning typically causes constriction of blood vessels, leading to gangrene in extremities—symptoms not reported in the 1518 outbreak. Additionally, ergot effects are usually short-lived, not lasting for days or weeks. The symptoms don’t match.
Mass Psychogenic Illness (Mass Hysteria): The leading modern explanation, championed by historian John Waller and others, is that the dancing plague was a case of mass psychogenic illness—a psychological phenomenon where physical symptoms spread through a group via social influence and belief.
This theory is supported by the historical context. Strasbourg in 1518 was a city under enormous stress:
• A series of recent famines had left the population malnourished and desperate
• Outbreaks of syphilis and other diseases were ravaging the region
• Economic hardship was widespread
• Religious anxiety was high, with fears of divine punishment pervasive in medieval Catholic society
• Multiple cases of “dancing mania” had been reported in the region over the previous century
In this environment of extreme stress, combined with widespread belief that Saint Vitus could inflict dancing curses, the initial case of Frau Troffea dancing could have triggered a psychological contagion. People genuinely believed they were cursed, and their bodies responded to that belief.
Mass psychogenic illness can cause very real physical symptoms. The brain, convinced something is happening to the body, can manifest genuine physical responses—including involuntary movements. The phenomenon is well-documented in modern medical literature and typically affects populations under significant stress.
Sydenham’s Chorea: Some researchers have suggested the dancers might have been suffering from Sydenham’s chorea, a neurological disorder that causes rapid, involuntary movements. However, this condition doesn’t typically affect large numbers of people simultaneously, nor does it usually last for weeks without pause.
Epilepsy or Encephalitis: Mass epileptic seizures or an outbreak of encephalitis (brain inflammation) have been proposed. However, neither condition matches the sustained, coordinated dancing movements described in historical accounts.
Not the First Dancing Plague
The 1518 Strasbourg outbreak was the most famous and best-documented dancing plague, but it wasn’t the first—or the last.
Similar outbreaks of dancing mania had been reported throughout Europe during the medieval and early modern periods:
• 1374: A massive outbreak occurred along the Rhine River, affecting thousands across multiple cities in modern-day Germany, Belgium, and the Netherlands. Dancers formed processions that traveled from town to town.
• 1428: A dancing epidemic struck the Schaffhausen region (modern Switzerland), where a monk named Johann Virdung documented dancers forming circles and continuing for hours.
• 1518: Besides Strasbourg, smaller outbreaks occurred in other parts of Alsace the same year.
• 1840s: One of the last recorded outbreaks occurred in Madagascar, where groups of dancers moved involuntarily for extended periods.
These earlier and later outbreaks support the mass psychogenic illness theory. Dancing mania was an established phenomenon in the cultural consciousness of medieval Europe. People knew about it, feared it, and believed it could happen. This cultural framework made the phenomenon more likely to occur and spread.
The Cultural Context: Fear and Faith
Understanding the Dancing Plague requires understanding the medieval mindset. The people of 1518 Strasbourg lived in a world very different from ours—a world where:
• Disease was interpreted as divine punishment for sin
• Saints could curse or bless communities based on their behavior
• The boundary between natural and supernatural was blurred
• Collective guilt and collective salvation were central to religious life
• The body was understood through humoral theory, not modern physiology
When Frau Troffea began dancing, the people of Strasbourg had a ready explanation: curse, punishment, or diabolical influence. This explanation was as real and valid to them as a medical diagnosis is to us. And once that belief took hold, it could manifest physical reality.
The phenomenon demonstrates the extraordinary power of belief and suggestion. When an entire community believes something can happen, when they’ve been primed by stress and fear, when they see others experiencing it, the mind can create physical symptoms that are entirely genuine to the sufferer.
Frau Troffea’s Fate
What happened to the woman who started it all? Historical records tell us remarkably little about Frau Troffea after those first desperate days of dancing. She was among those taken to the shrine of Saint Vitus. Whether she survived the ordeal is uncertain—some accounts suggest she recovered, others are silent on her fate.
Did she deliberately begin dancing, perhaps as an act of religious ecstasy or mental breakdown? Or was her initial dance also involuntary, perhaps caused by some individual medical condition that then triggered the mass event? We’ll never know for certain.
What we do know is that her actions—whether voluntary or not—sparked one of the strangest epidemics in human history.
Modern Parallels
While the Dancing Plague sounds like something from a fantasy novel, similar phenomena occur even today:
• In Tanzania in 1962, a laughing epidemic affected 1,000 people, with uncontrollable laughter lasting for months
• In 2011, hundreds of students in New York developed involuntary tics and vocalizations in what was diagnosed as mass psychogenic illness
• In 2012, a similar outbreak of tics and seizures affected teenage girls in Le Roy, New York
• Throughout history, numerous “mystery illnesses” affecting specific communities have been identified as mass psychogenic phenomena
These modern cases help validate the explanation for the 1518 dancing plague. They demonstrate that under the right conditions of stress, belief, and social influence, groups of people can develop very real physical symptoms that spread like a contagion—not through germs, but through psychology.
The Legacy
The Dancing Plague of 1518 remains one of history’s most bizarre and unsettling events. It has inspired:
• Numerous academic studies on mass psychogenic illness
• Works of art, music, and literature exploring the event
• The term “St. Vitus’s Dance” as a historical name for certain movement disorders
• Ongoing debates among historians, psychologists, and medical researchers
In 2017, exactly 499 years after the original outbreak, the city of Strasbourg commemorated the event with art installations and performances, acknowledging this strange chapter in its history.
The narrow streets of Strasbourg today show no trace of the horror that unfolded in the summer of 1518. Tourists walk through the same squares where hundreds once danced themselves to death, unaware they’re treading on ground soaked in one of history’s strangest tragedies. The Dancing Plague stands as a reminder of the extraordinary power of the human mind—both its fragility under stress and its ability to manifest belief into physical reality. In an age that had endured famine, disease, and religious terror, the people of Strasbourg created their own nightmare, and then danced within it until exhaustion, death, or divine intervention set them free. Frau Troffea stepped into that July street and began to dance, and in doing so, she opened a door to something that science still struggles to fully explain. The music has long since stopped, but the mystery remains: How can belief alone make a body dance until it dies? How can fear spread like infection through a community? And in our own modern world, filled with its own anxieties and stresses, what strange contagions might we be creating without even knowing it? The dancers of 1518 have long since rested. But their warning echoes across the centuries: the mind can be as dangerous as any plague, and sometimes the most terrifying threats come not from outside, but from within.