In July 1518, a woman in Strasbourg, then a free city of the Holy Roman Empire and today part of France, began to dance in the street. Later chronicles give her name as Frau Troffea. She kept going for days. Others joined her. By August, contemporary sources say dozens of people were dancing, and some accounts put the number much higher.
It has the ring of legend, yet the evidence is solid. The dancing plague of 1518 is one of the better documented cases of what historians call a "dancing mania," because the city's own records, sermons and physicians' notes have survived.
What the documents say
The surviving evidence includes notes from the city council, the writings of local chroniclers, and remarks by the physician Paracelsus, who visited Strasbourg some years afterward and wrote about the event.
They agree on a handful of points:
- The dancing began in mid-July 1518 and went on into September.
- Many people were affected, far more than one or two.
- The authorities took it seriously and tried several remedies.
- Some of the dancers were reported to have collapsed, and some chroniclers say people died.
The numbers are the weakest part of the story. It is common to read that 400 people danced, or that 15 people a day died. Those figures appear in later retellings. Historians who have gone back to the archive, John Waller most notably in his book A Time to Dance, a Time to Die, treat the higher counts with caution. The council records confirm a serious outbreak. They do not give a precise death toll.
The city's strange remedy
The most famous detail also happens to be one of the best supported. The council, on the advice of physicians, decided at first that the dancers had "hot blood" and needed to dance it out of their systems. So the city cleared space for them, including guild halls and a grain market, and hired musicians, and even strong men, to keep the dancers moving and hold them upright.
It did not work. The dancing spread. The authorities then reversed themselves. They banned public music and dancing, with exceptions for weddings and similar occasions, and sent the afflicted to a shrine of Saint Vitus in the hills near Saverne. There the dancers were given small crosses and red shoes and led through rituals meant to free them from the saint's curse.
After that, the outbreak died away.
Why Saint Vitus?
In the late Middle Ages, many people in the Rhine region believed that Saint Vitus could curse people with uncontrollable dancing, and could cure them of it as well. That belief matters a great deal. If people in Strasbourg already thought such an affliction was possible, and that a saint might be punishing them, it would shape how they understood their own symptoms and those of their neighbors.
The name lived on in medicine. "Saint Vitus' dance" was later applied to Sydenham's chorea, a neurological disorder that causes jerky movements, usually in children after a strep infection. That condition is real, but it is a poor match for what happened in 1518, since it does not spread through a crowd and does not make people dance for days.
What might explain it
Several explanations have been put forward. None can be proven.
Ergot poisoning. Ergot is a fungus that grows on rye, especially in damp weather. It contains compounds that can cause convulsions and hallucinations, and this theory comes up often. The difficulty is that ergot poisoning tends to restrict blood flow and cause painful spasms, and it is hard to see how it would let people dance in a coordinated way for days on end. Nor does it explain why the outbreak passed from person to person in a single city and then stopped after a pilgrimage.
Mass psychogenic illness. This is the explanation most historians now favor. The term describes situations in which a group of people develop physical symptoms with no organic cause, usually under heavy stress and in a setting where those symptoms make cultural sense. Strasbourg in 1518 was under great strain. There had been bad harvests, high bread prices, disease, including smallpox and syphilis, and widespread poverty. People also believed in the Saint Vitus curse. Waller argues that this mix of desperation and belief created the conditions for a trance-like state to spread.
Staged or exaggerated accounts. Some skeptics suggest the event was smaller than described, or that chroniclers confused it with religious processions. The council records make it hard to wave away entirely, but they do justify some caution about its scale.
Was it unique?
No. Chroniclers describe similar outbreaks in several places along the Rhine and the Moselle and in the Low Countries, including a large episode in 1374. What sets 1518 apart is the paperwork. Strasbourg kept records, and later writers such as Paracelsus took an interest in what had happened.
How to read stories like this
The dancing plague makes a good test case for any "strange but true" history story.
- Find the oldest source. For 1518, that means the council minutes and the chroniclers writing close to the time.
- Separate the event from the numbers. The event is well documented. The death toll is not.
- Be suspicious of tidy explanations. "It was ergot" is satisfying, but it does not fit all of the evidence.
- Ask what people believed at the time. Beliefs about Saint Vitus are part of the explanation, and more than mere background.
Why it still fascinates people
Part of the appeal is the picture itself: a medieval town, musicians playing, exhausted people unable to stop. The deeper interest, though, lies in how stress, belief and community can produce symptoms that are entirely real to the people who have them. Nothing about that is confined to the Middle Ages. Modern medicine still sees cases of mass psychogenic illness, usually in schools or workplaces under pressure.
The dancers of Strasbourg were not faking. Something happened to them. We simply cannot say for certain what it was.
Sources
- John Waller, A Time to Dance, a Time to Die: The Extraordinary Story of the Dancing Plague of 1518 (Icon Books, 2008).
- John Waller, "A forgotten plague: making sense of dancing mania," The Lancet, vol. 373, 2009.
- Encyclopaedia Britannica, "dancing plague of 1518."
- Paracelsus, writings on chorea and dancing mania (16th century), as discussed by Waller.