The dancing plague of 1518, also called the dance epidemic of 1518 (in French: Épidémie dansante de 1518; in German: Straßburger Tanzwut), was an unusual event that happened in Strasbourg, Alsace (modern-day France), in the Holy Roman Empire between July and September 1518. Between 50 and 400 people danced continuously for weeks. Scientists have proposed several explanations for this event, with one common idea being stress-induced mass hysteria, as suggested by John Waller. Another theory is ergot poisoning. There is disagreement about how many people died during this time.

History

In July 1518, a woman named Frau Troffea and her daughter, Fräulein Emma Götz, began dancing uncontrollably on a narrow, cobbled street near their home in Strasbourg. According to Ned Pennant-Rea, Frau Troffea started dancing on July 14th with no music. Some people who saw her began copying her movements, including her husband. Within days, more than thirty people joined in, dancing so intensely that only death could stop them. Frau Troffea continued dancing for a week, resting only to sleep. Soon, thirty others joined her. By August, between 50 and 400 people were affected. The dancers moved in jerky, stiff ways, often collapsing from exhaustion, hunger, or thirst. Their arms flailed, their eyes looked empty, and their feet swelled with blood. Some cried for help. Doctors at the time believed the cause was "hot blood," a theory that excess body heat led to uncontrollable movements. Historians disagree about how many people died, but some say up to 15 people died daily during the outbreak. No one knew the cause, so no cure was found. By early September, the outbreak ended.

Historical records, including notes from doctors, church sermons, and city council documents, confirm that the victims danced. It is unknown why they began. The dancing spread quickly and lasted so long that local authorities became involved. The city council allowed doctors to treat the affected people, who were told to "dance themselves free." Some reports say guild halls were rebuilt to hold dancers, and musicians and strong people were hired to help them. This plan failed, and the council banned public dancing because people feared it was punishment from Saint Vitus. To be "free of sin," many joined the dancing. At the time, people believed demonic possession or divine punishment caused the dancing. To stop it, only those with religious authority could help. The council banned music and ordered dancers to visit the shrine of Saint Vitus. Participants wore red shoes sprinkled with holy water, held small crosses, and used incense and Latin prayers. Reports said some were "forgiven by Vitus," suggesting the ritual worked. The outbreak stopped in September when remaining dancers were taken to a mountain chapel to pray for forgiveness.

Similar events happened in medieval times. In the 11th century, Cölbigk, Saxony, had a dancing outbreak believed to be divine punishment. In the 15th century, a woman in Apulia, Italy, was bitten by a tarantula, causing her to dance uncontrollably. Scholars like Athanasius Kircher believed the cure was to dance and listen to music. At the time, people thought dancing, rest, or cooling the body could cure "hot blood." Some also used chemicals on ticklish areas to stop the dancing.

Veracity of deaths

There is disagreement about whether people died during the dancing plague. Some sources say the plague killed about fifteen people each day, but records from the city of Strasbourg at the time do not mention the number of deaths or whether anyone died. No sources from that time describe any deaths. Ned Pennant-Rea also says the total number of deaths is unknown. However, if the claim of fifteen deaths per day were true, the total number of deaths might have been "into the hundreds."

The main source for the claim that people died is John Waller, who has written articles and the book A Time to Dance, a Time to Die: The Extraordinary Story of the Dancing Plague of 1518. The sources Waller cites that mention deaths come from later accounts of the event. There is also uncertainty about the identity of the first dancer, who was either an unnamed woman or a woman named "Frau Troffea," and the number of dancers involved, which ranged between 50 and 400. Out of six written records from the time, four describe "Lady Troffea" as the first dancer.

Modern theories

Some people think the dancing may have been caused by food poisoning from a harmful chemical made by ergot fungi (called ergotism). This fungus often grows on grains like rye used for making bread. A key chemical in ergot is ergotamine, which is similar to the drug LSD-25. This chemical was used to create LSD-25. The same fungus has also been linked to other historical events, such as the Salem witch trials.

In The Lancet, John Waller says the ergotism theory is unlikely because people poisoned by ergot would not have danced for days. Also, it is improbable that so many people would react the same way to the fungus’s chemicals. The theory also does not explain why most outbreaks happened near the Rhine and Moselle rivers, which share water but have different climates and crops.

The dancing could have been caused by a mental health condition called psychogenic movement disorder, which happens during mass hysteria or mass psychogenic illness. In these cases, many people suddenly show the same strange behavior. This behavior spreads quickly, like an epidemic. It may have been caused by high stress levels from difficult times, such as the hardships faced by people in Alsace during the early modern period.

Waller suggests the dancing was "stress-induced psychosis" on a large scale. The area where the dancing happened had problems with hunger and disease, and the people were often superstitious. This, Waller believed, led to an "altered state of consciousness," causing people to lose their sense of reality. Seven other cases of dancing plagues were reported in the same region during the medieval era, with dancers also described as being in a trance.

This mental illness may have caused a condition called chorea, from the Greek word khoreia meaning "to dance." Chorea involves sudden, uncontrollable movements that move from one body part to another. In the Middle Ages, different types of chorea were named, such as St. Vitus' dance, St. John's dance, and tarantism. These terms referred to separate outbreaks of "dancing mania" in central Europe, especially during the time of the plague.

Pop culture and media

The event inspired Jonathan Glazer's 2020 short film Strasbourg 1518.

This event inspired the 2022 choral song "Choreomania" by Florence and the Machine. The song was the third track on the album Dance Fever, which borrowed its name from the song.

The book series A Collection of Utter Speculation released a book titled The Dancing Plague: A Collection of Utter Speculation in 2022. This book is a fictional account of the events that occurred in Strasbourg.

The event is mentioned in the 2024 song "RATKING 1518," both in the title and the lyrics. The song was created by the rap duo Grim Salvo.

The event inspired the music video short film for the 2025 joint release of songs "In The Sound of Breathing" and "Opening" by Loreen and Ólafur Arnalds. The project was named SAGES.

The event is the subject of the song "Died of Dancing" by the Australian progressive rock band Toehider. The song's lyrics directly mention "Mrs. Troffea" and "hot blood."