Dancing Plague of 1518
The Dancing Plague (or Dance Epidemic) of 1518 was a case of dancing mania that occurred in Strasbourg, Alsace (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, some of those affected died of 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. Some 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Historical documents, including "physician notes, cathedral sermons, local and regional chronicles, and even notes issued by the Strasbourg city council" are clear that the victims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, some even to their deaths.
As the dancing plague worsened, concerned nobles sought the advice of local physicians, who ruled out astrological and supernatural causes, instead announcing that the plague was a "natural disease" caused by "hot blood." However, instead of prescribing bleeding, authorities encouraged more dancing, in part by opening two guildhalls and a grain market, and even constructing a wooden stage. The authorities did this because they believed that the dancers would recover only if they danced continuously night and day. To increase the effectiveness of the cure, authorities even paid for musicians to keep the afflicted moving. Some of the dancers were taken to a shrine, where they sought a cure for their affliction.
Historian John Waller stated that a marathon runner could not have lasted the intense workout that the men and women died from hundreds of years ago. 
- Viegas, Jennifer (1 August 2008). "'Dancing Plague' and Other Odd Afflictions Explained". Discovery News. Discovery Communications. Archived from the original on 13 October 2012. Retrieved 6 May 2013.
- Waller, John C. (September 2008). "In a spin: the mysterious dancing epidemic of 1518". Endeavour (Elsevier) 32 (3): 117–121. doi:10.1016/j.endeavour.2008.05.001. ISSN 0160-9327. PMID 18602695.
- Backman, Eugene Louis (1977) . Religious Dances in the Christian Church and in Popular Medicine. Westport, CT: Greenwood Press. ISBN 978-0-8371-9678-7.
- Waller, John (2008). A Time to Dance, A Time to Die: The Extraordinary Story of the Dancing Plague of 1518. Thriplow: Icon Books. ISBN 978-1-84831-021-6.
- Waller, John (2009). The Dancing Plague: The Strange, True Story of an Extraordinary Illness. Naperville, IL: Sourcebooks, Inc. ISBN 978-1-4022-1943-6.