The Dancing Plague of 1518

The Dancing Plague (or Dancing Epidemic) of 1518 was a case of dancing mania that occurred in Strasbourg, Alsace, France (then part of the Holy Roman Empire) in July 1518. Numerous people took to dancing for days without rest, and over the period of about one month, most of the people died from heart attack, stroke, or exhaustion.

The outbreak began in July 1518, when a woman, Frau Troffea, began to dance fervently in a street in Strasbourg. This lasted somewhere between four to six days. Within a week, 34 others had joined, and within a month, there were around 400 dancers. Most of these people eventually died from heart attack, stroke, or exhaustion

Historical documents, including "physician notes, cathedral sermons, local and regional chronicles, and even notes issued by the Strasbourg city council" are clear that the victims danced. It is not known why these people danced to their deaths, nor is it clear that they were dancing willfully. - Wikipedia

Say what you want, I still don't believe this really happened...

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