In 1518, One Woman Started Dancing in the Street. Four Hundred People Followed. They Could Not Stop.

It is the middle of July in Strasbourg, 1518 — a city in the Holy Roman Empire sitting on the Rhine, already battered that year by famine, syphilis, and the kind of generalized misery that makes a community's collective nervous system fragile. A woman named Frau Troffea steps into the street in front of her house and begins to dance. Not performing. Not celebrating. Just — dancing. Arms moving, feet moving, no music playing. Her husband watches from the doorway, presumably confused. She does not stop.

She dances for roughly six days. Her feet blister and bleed through her shoes. She sleeps when she collapses and resumes when she wakes. On approximately the fifth day, a neighbor joins her. Then another. Then another. By the end of the first week, thirty-four people are dancing in the streets of Strasbourg. By the end of the month, the count has reached somewhere around four hundred.

Contemporary observers, to their credit, understood this was a crisis. Frau Troffea was taken before the city council, examined, and ultimately sent — with her still-dancing company — to a shrine outside the city. This did not work. She came back. More people came with her. By August the epidemic was at its peak, and the city of Strasbourg was facing a public health problem it had absolutely no framework for.

The Problem With the Cure

The Strasbourg city council convened and consulted physicians. The physicians reached a diagnosis: the dancing was caused by "hot blood." The afflicted had blood that was too warm, too agitated, and the prescribed remedy was to let them dance it out completely. If they stopped early, it would be worse. You had to let the heat exhaust itself.

The council accepted this medical opinion without visible skepticism and did the following: they opened the guildhall and the grain market as dedicated dance stages. They hired professional dancers to accompany the afflicted, to keep them moving in a structured way rather than chaotically in the streets. They hired musicians — fiddlers, drummers — to play continuously, day and night. They stationed strong men nearby to catch anyone who fell. The official position of the city of Strasbourg, in the summer of 1518, was that the correct treatment for a dancing epidemic was more dancing, with better music.

This was not the correct call. The dancing continued. More people joined. Contemporary accounts — Sebastian Münster's Cosmographia, written some decades later, and records kept by Strasbourg city officials — describe people dancing until their feet were destroyed, until they had broken bones, until they were bleeding from their shoes. Families dragged relatives home who returned to the streets as soon as they were unrestrained. The professional dancers began showing symptoms themselves.

At the peak, contemporary sources record deaths reaching fifteen per day — from heart failure, from stroke, from sheer physical exhaustion. Historians treat this number with appropriate caution, as record-keeping in the grip of a public panic is rarely precise. What is clear is that people died. The city had taken a public health crisis and given it a stage and an orchestra.

The Saint Who Presided Over the Problem

By August, someone in the council appears to have reconsidered. The musicians were sent away. The dance floors were closed. The afflicted were stripped of their red shoes — a specific detail from the historical record, unexplained — and marched in pilgrimage to the shrine of St. Vitus at Saverne, a town roughly thirty miles away. There they were to pray for relief from their affliction.

St. Vitus, you should know, is the patron saint of dancers. Also epileptics. Also people who oversleep — his intercession was specifically invoked for those suffering from involuntary physical movement, which is precisely why the epidemic eventually became known as "St. Vitus' Dance." That name later migrated into medicine entirely: Sydenham's chorea, a real neurological disorder characterized by involuntary jerking movements, is still informally called St. Vitus' Dance to this day. The city of Strasbourg, in its desperation, sent their afflicted citizens to beg mercy from the one saint with literal jurisdiction over the thing they were afflicted with. This is either deeply logical or deeply ironic, and I've been turning it over for weeks.

The pilgrimage appears to have worked, or at least the epidemic declined in September 1518. Whether this was the shrine, or the removal of the musicians, or the cooling of the summer heat, or the simple passage of time, nobody can say with certainty. By autumn it was over. Strasbourg moved on.

What Actually Happened

The leading modern scholar on the Dancing Plague is John Waller, a historian of medicine whose 2008 book A Time to Dance, A Time to Die is the definitive account. His argument — supported by the social history of Strasbourg in 1518 — is that this was mass psychogenic illness. The years preceding the epidemic had been catastrophic: crop failures, smallpox outbreaks, syphilis, famine. The community was under extreme and sustained psychological stress. In that environment, Waller argues, one person's physical breakdown became a contagion — not of germs, but of the nervous system. People who watched the dancing, already primed by terror and exhaustion, began to exhibit the same symptoms. The expectation of affliction, in communities where spiritual possession and divine punishment were live fears, could produce real physical symptoms at scale.

The competing theory is ergot poisoning. Ergot is a fungus that grows on rye in wet conditions and can cause convulsions, hallucinations, and involuntary movement. 1518 was a wet year. The region had experienced crop problems. It's not impossible. But ergot poisoning tends to produce hallucinations and gangrene more consistently than it produces sustained, coordinated dancing, and the selectivity of the outbreak — some people in the same community, not others, over the course of weeks rather than all at once — fits psychogenic illness better than a shared food supply.

The psychogenic argument is more compelling to me, but I want to be honest: nobody was there and no tissue samples survive from 1518. What we have are chronicles, council records, and one dismissive reference in Paracelsus, the Renaissance physician and alchemist, who attributed it to "wanton and loose persons." He was wrong about the cause but at least he was looking for one, which puts him ahead of the physicians who prescribed more dancing.

Why You Should Think About This

There have been other dancing plagues. Aachen, 1374. Liège, 1374. Metz, 1518. Smaller outbreaks scattered across the medieval and early modern European record. Strasbourg 1518 is not a one-time aberration — it is the best-documented instance of something that kept happening in crowded, stressed communities. The fact that it doesn't happen in the same form today is interesting. Not because we've become more rational — mass psychogenic illness is well-documented in the modern era, in factories and schools and online communities. But the specific shape it takes changes. The symptoms available to the nervous system under extreme duress are, in part, shaped by cultural expectation. In a world where God's anger was a live and immediate threat, and where St. Vitus was known to strike people with dancing, the nervous system had a template. It used it.

The Strasbourg Dancing Plague is, at bottom, a story about what a community under impossible pressure does to itself. The dancing was real. The deaths were real. The city council's genuinely catastrophic medical intervention was real. But the cause was, in a meaningful sense, the year 1518 itself — the accumulated weight of famine and plague and fear pressing down on a population until something simply broke loose and started moving. The body, when the mind is out of options, does something. In Strasbourg that summer, it danced.