In July 1518, a woman named Frau Troffea entered a street in Strasbourg, France, and began to dance wildly without stopping for four or six days. By the end of the week another 34 people had joined their dance, and after a month the number of dancers was 400.
Consulted the authorities of the city, it was prescribed that the dancers had to dance more to cure their tormented bodies, reason why they were habilitated dance halls and even they contracted musicians and professional dancers to animate the party.
But by the end of the summer dozens of people had died in the Alsatian city because, strokes or exhaustion provoked by that irrepressible activity.
For centuries, this strange event known as the dance plague of 1518, has perplexed scientists, who have tried to find a cause for this meaningless, intense and ultimately fatal dance. The historian John Waller, author of a book on the subject, believes that these people were in a state of trance, otherwise they could not have endured so much time dancing without stopping.
Other authors have looked for a biological or chemical origin to this event, as for example that the inhabitants of Strasbourg had ingested ergot, a fungus with psychotropic properties that grows in the humid rye stems.