The Strasbourg Summer When People Danced to Death

In July 1518, a woman named Frau Troffea stepped into a street in Strasbourg and began to dance. She did not stop. Within a week, around thirty more residents had joined her. Within a month, the count was somewhere near four hundred, jerking and stumbling through the streets in midsummer heat.

Contemporary chronicles, including those of the physician Paracelsus a few years later, recorded that some of the dancers collapsed from exhaustion, strokes, or heart attacks. The exact death toll is disputed, but city records mention multiple fatalities a day at the peak.

What makes the episode strange is the official response. Strasbourg's authorities, after consulting local physicians, decided the affliction was a "natural disease" of overheated blood. Their prescribed cure was more movement. They cleared two guildhalls and the open-air grain market, hired musicians and professional dancers, and instructed the sufferers to dance it out of their systems. The death rate climbed.

The favored modern explanations split between two camps. One blames ergotism — poisoning from a fungus that grows on damp rye and produces convulsions and hallucinations, though ergot tends to cut off blood flow to the limbs, making sustained dancing unlikely. The other, argued by historian John Waller, treats the outbreak as a mass psychogenic illness, triggered by a brutal year of famine, smallpox, and syphilis, and shaped by a regional folk belief that Saint Vitus could curse sinners with compulsive dance.

The dancing tapered off in September after the city sent the worst-affected to a shrine in the mountains. No one ever satisfactorily diagnosed the disease, and there has not been a comparable outbreak since.