The dancing plague of 1518, or dance epidemic of 1518

The dancing plague of 1518, or dance epidemic of 1518 (French: Épidémie dansante de 1518), was a case of dancing mania that occurred in Strasbourg, Alsace (modern-day France), in the Holy Roman Empire from July 1518 to September 1518. Somewhere between 50 and 400 people took to dancing for weeks. There are many theories behind the phenomenon, the most popular being stress-induced mass hysteria, as suggested by John Waller. Other theories include ergot and religious explanations. There is controversy concerning the number of deaths.