This really gives "dance like there's no tomorrow" a new meaning. The Dance Plague of 1518 broke in July of that year, when a woman, Frau Troffea, began to dance fervantly in a street in Strasbourg, Alsace (then part of the Roman Empire). Within a week, 34 others had joined, and within a month, there were around 400 dancers dancing on the same street.
Numerous people took to dancing for days without rest. Over a period of a month, people were literally dropping dead from heart attack, stroke, or exhaustion but the deadly dance party continued on. As the Dance Plague worsened, concerned nobles sought the advice of local physicians who told them that the plague was a "natural disease" caused by "hot blood."
Rather than prescribing bleeding, the authorities encouraged more dancing, even built a wooden stage for the dancers and hired musicians, because they believed that the dancers would only recover if they got their sick moves out of their system.
To this day, it is not known why exactly everyone was dancing.
