The Dancers of Strasbourg and the Cure That Fed the Plague

In July 1518, a woman known in surviving records as Frau Troffea is reported to have begun dancing in a street in Strasbourg and to have continued for days. Within weeks, dozens and perhaps several hundred others were said to have joined her, some dancing until they collapsed. City authorities, apparently believing the dancers needed to exhaust the affliction, are reported to have arranged a stage and musicians, a decision that seems to have made matters worse.

Modern explanations differ. A theory that the dancers had eaten bread contaminated by ergot is widely repeated, yet historians note that ergot poisoning tends to cause convulsions and restricted blood flow, not coordinated dancing for days. The historian John Waller has argued that the episode was more likely mass psychogenic illness, spreading among people already in deep distress after famine and disease.