In July 1518, around 400 people took to the streets of Strasbourg, France (formerly part of the Holy Roman Empire) to dance for days without rest.
The dancing mania lasted over the course of a month and even caused some dancers to die of exhaustion, stroke, or heart attack.
Uh… Dancing mania? Come again?
Yes, that’s right. Endless dancing that actually killed people, known as a “dancing mania”, was common enough to be recognized as a social phenomenon in 14th-17th century Europe.
The first major outbreak occured in Aachen in 1374 and it spread for hundreds of years across many countries.
In an attempt to treat the “mania”, musicians would sometimes play music alongside the dancers. However this technique often backfired, causing onlookers to join in.
So back to the dancing in Strasbourg
The outbreak in Strasbourg initially began when a woman, Mrs. Troffea, began to erratically dance in the streets. She managed to keep this up for an astounding 4-6 days, attracting attention from the locals.
Within the week 34 other townsfolk joined in. At the end of the month, the total number of dancers rose to 400 (predominantly female).
Over the course of July, it was estimated that the raucous dancing killed 15 people per day due to heart attacks, strokes, or exhaustion.
To this day it is still not known what caused the people of Strasbourg to dance. Concerned nobles brought in the help of physicians who claimed that the outbreak was a “natural disease” due to “hot blood”.
Local authorities exacerbated the issue by opening two guildhalls and a grain market to be used as dancing grounds. They even paid local musicians to help wear out the dancers faster.
This didn’t work. Instead it possibly caused more deaths as dancers were moving faster and with more motivation.
“A marathon runner could not have lasted the intense workout that these men and women did hundreds of years ago,” remarked Historian John Waller.
Modern theories on what causes “dancing mania”
Besides Kevin Bacon, contemporary historians believe that food-poisoning by toxic and psychoactive fungi may have caused the disease.
Ergot fungi, which commonly grows on wheat and rye, has many hallucinogenic properties similar to LSD and is even the substance from which LSD-25 was originally synthesized.
This same fungus has been implicated in other historical phenomenon such as the Salem witch trials.
Historian John Waller feels as though the dancing may have been a result of “stress-induced psychosis” due to the region being plagued with disease and starvation.
Whatever caused it, historians can agree on one thing: Dancing mania was one of the earliest-recorded forms of mass hysteria.