The Dancing Plague of 1518

In July 1518, in the streets of Strasbourg, a woman named Frau Troffea stepped out of her house and began to dance. She did not stop. She danced for hours, then days. Within a week, dozens had joined her. Within a month, an estimated four hundred. Some danced themselves into strokes. Some died of exhaustion. The civic authorities, baffled, eventually built a stage and hired musicians, reasoning that the dancers would only recover if they could dance the affliction out of themselves.

It is one of the strangest documented events in European history. Two competing explanations have endured: mass psychogenic illness, driven by the famines, plagues, and apocalyptic dread of the era — and ergotism, the same fungal poisoning later implicated at Salem.

The case for the fungus

Ergot intoxication can produce involuntary motor spasms violent enough to look, to a sixteenth-century witness, like uncontrollable dancing. The Rhine valley grew rye. The summer of 1518 followed a damp spring. The combination is exactly what Caporael would later flag at Salem. The historian John Waller, the leading modern scholar of the plague, rejects ergot — he argues the victims would have been too physically incapacitated to dance for days — and favors a trance-state explanation rooted in religious terror of Saint Vitus.

“There was a fever in the rye and a fever in the soul; perhaps the body could not tell the difference.”

Either way, the bread was suspect

Whether the dancers were poisoned, possessed, or pushed past breaking by stress and theology, the episode is a reminder of how thin the membrane is between body and belief. A whole town's mind can come loose at once. Sometimes it takes a saint. Sometimes it only takes a damp summer.