A mysterious dancing plague swept through Strasbourg in 1518
In July 1518, a woman named Frau Troffea stepped into a street in Strasbourg and began dancing fervently. Within weeks, over 500 people had joined her, dancing uncontrollably day and night without music. Local authorities tragically encouraged more dancing by constructing stages and hiring musicians, believing victims needed to dance it out. Dozens of participants eventually collapsed and died from extreme exhaustion, stroke, or heart attack.
An Uncontrollable Movement in the Streets
In the middle of July 1518, in the narrow streets of Strasbourg, then a free imperial city within the Holy Roman Empire, a woman identified in historical records as Frau Troffea stepped out of her home and began to dance. There was no musical accompaniment, no festival underway, and no visible celebration. Yet she danced with intense, relentless fervor, continuing for hours until she collapsed from exhaustion, only to resume once she had regained minimal strength.
Troffea's solitary movement did not remain isolated for long. Within a few days, several onlookers had joined her in the streets, caught in the same relentless physical compulsion. Within a month, the number of dancers had climbed into the dozens, and contemporary chronicles estimate that as the weeks wore on, somewhere between several dozen and upwards of four hundred people were overtaken by the mania, dancing without pause under the summer sun.
The City Council and the Theory of Hot Blood
As the disruption threatened the civil order and commerce of Strasbourg, the city council convened to find an explanation and an intervention. Rather than immediately turning to the clergy or declaring demonic possession, the magistrates consulted the local medical elite. The physicians examined the dancers and ruled out astrological alignment or direct demonic interference, diagnosing the condition instead as a natural disease caused by an overheating of the blood.
According to prevailing humoral theory, an excess of black bile or overheated blood could induce severe mania and delirium. The recommended treatment, however, proved catastrophic. The physicians advised that the afflicted could not be forcibly restrained without risking fatal internal humors; instead, they had to dance the affliction out of their systems until the feverish heat broke naturally.