In July 1518, a dancing plague hysteria started in the city of Strasbourg (then part of the Roman Empire) when a woman known as Frau Troffea twisted, twirled, and shook on the street for almost a week. After some time, close to three-dozen other Strasbourg residents also began dancing like Troffea. The number of people affected by the dancing bug kept growing daily. City authorities were seriously alarmed.

The solution to the dancing problem was more dancing

To address the uncontrollable dancing of the residents, civic and religious leaders thought that more dancing was the solution (fight fire with fire!) Instead of stopping them, they arranged for guildhalls for the dancers to gather in, musicians to accompany the dancing, and professional dancers to help the victims to continue dancing. Shocker: It didn’t work. Four-hundred people felt the groove and up being “victims” of the dancing compulsion.

Possible reasons for the uncontrollable and unstoppable dancing

The dancing plague in Strasbourg went on for two months. Many dancers collapsed from exhaustion. Some even died from strokes and heart attacks. Now we’ve all been taken by a sweet beat before, but why the mass dance off?

Some believed that it was caused by demonic possession, a common explanations for the unexplained back in the day. Doctors of the time speculated the cause was overheated blood. Investigators from the 20th century, on the other hand, believe that the condition may have been caused by bread made from rye flour contaminated with the fungal disease ergot (a possible culprit in the Salem witch trials) which causes convulsions. Sociologist Robert Bartholomew asserts that the dancers may have been followers of heretical sects and their dancing was made to entice divine favor.

Historians, however, believed that the dancing plague was caused by some form of mass psychogenic disorder which usually occurrs among people suffering from extreme stress. American medical historian John Waller pointed out that 1518 was a year of famine, smallpox, and syphilis — all of which were powerful stressors that could have affected the residents of Strasbourg.