The Dancing Plague of 1518 was a bizarre and mysterious case of dancing mania that occurred in the city of Strasbourg, Alsace (then part of the Holy Roman Empire, now modern-day France). Beginning in July of that year, hundreds of people began to dance manically and uncontrollably in the city streets for days on end. With no music and expressions of agony on their faces, the dancers continued their frenzied movements until they collapsed from exhaustion, dehydration, or heart attack. The phenomenon lasted for over a month and resulted in the deaths of dozens of people.
The Beginning of the Mania: Frau Troffea
The incident began with a single person. In mid-July 1518, a woman identified in historical records as Frau (Mrs.) Troffea stepped out of her house and began to dance silently and fervently in the street. There was no music, and she appeared to be in a trance-like state. According to witnesses, she continued to dance for nearly a week, stopping only for brief periods of sleep.
Within a week, her strange and solitary performance had attracted followers. Around three dozen other citizens of Strasbourg were seized by the same compulsion and joined her in the streets. The phenomenon quickly escalated. By August, the number of uncontrollable dancers had swelled to approximately 400 people.
The Bizarre Official Response
The city’s authorities, including the magistrate and physicians, were baffled by the affliction. After ruling out astronomical and supernatural causes, they diagnosed it as a medical condition caused by “hot blood.” Their prescribed cure, based on the medical theories of the time, was as bizarre as the plague itself: they believed the victims needed to dance the fever out of their systems. Consequently, the authorities decided to encourage the dancing.
They took several extraordinary measures:
- Public Dancing Spaces: They cleared out two of the city’s guildhalls and the open-air grain market to provide dedicated spaces for the dancers.
- A Wooden Stage: They even constructed a large wooden stage in the horse market to accommodate the spectacle.
- Hired Musicians: To keep the afflicted moving, the city council hired professional musicians to play pipes, horns, and drums.
This well-intentioned but misguided therapeutic approach had the opposite effect. The public spectacle and the presence of music seemed only to encourage more people to join the mania. The non-stop exertion in the summer heat proved fatal. Contemporary reports state that at the plague’s peak, it was claiming up to 15 lives per day due to strokes, heart attacks, and sheer exhaustion.
Theories: What Caused the Dancing Plague?
The true cause of the Dancing Plague of 1518 has been debated by historians and scientists for centuries. There is no single, definitive answer, but the main theories fall into two categories.
Theory 1: Ergot Poisoning (Ergotism)
One of the earliest scientific theories was that the dancers were suffering from ergotism. Ergot is a toxic mold that grows on damp rye, which was a staple grain in the region. Ingesting ergot-contaminated flour can cause a condition known as St. Anthony’s Fire, with symptoms including convulsions, muscle spasms, and vivid hallucinations. This could potentially explain the uncontrollable movements.
Arguments against this theory: While ergot can cause spasms, it is unlikely to produce the coordinated, sustained dancing described in historical accounts. Furthermore, ergot poisoning typically restricts blood flow to the extremities, which would make dancing for days physically impossible.
Theory 2: Stress-Induced Mass Hysteria
This is the most widely accepted explanation among modern historians. Mass hysteria, or more formally Mass Psychogenic Illness, is a phenomenon where a group of people experiences a collective outbreak of unusual thoughts, feelings, or behaviors with no apparent physical cause. The conditions in Strasbourg in 1518 were ripe for such an event.
- Extreme Hardship: The region was suffering from a period of severe famine, widespread disease (including syphilis and leprosy), and extreme poverty.
- Superstition and Fear: The population was deeply superstitious and lived in a state of constant psychological stress and fear of divine wrath. Local beliefs included a story of a saint named St. Vitus, who could inflict a curse of compulsive dancing.
- Psychological Contagion: In this high-stress environment, the sight of Frau Troffea’s dancing could have acted as a trigger. For others suffering from the same psychological pressures, the behavior became a contagious, physical manifestation of their collective anxiety and trauma.
| Theory | Key Evidence | Primary Weakness |
|---|---|---|
| Ergot Poisoning | Ergot mold on rye can cause hallucinations and muscle spasms. | Symptoms do not align well with sustained, coordinated dancing. Ergotism usually impedes movement. |
| Mass Psychogenic Illness | The region was under immense psychological stress from famine and disease. Historical precedent for similar outbreaks exists. | It is difficult to definitively prove after the fact. The scale of the event is extreme even for mass hysteria. |
The Dancing Plague of 1518 eventually subsided when the authorities changed tactics. They banned all music and public dancing, and the remaining dancers were taken to a shrine to be prayed over. The mania gradually faded away, leaving behind a bizarre and tragic chapter in European history. It remains a powerful and unsettling example of the complex relationship between the mind, the body, and society under extreme pressure. Its study offers fascinating parallels to modern psychology concepts like the bystander effect, which also explores unusual social behaviors. The historical context of the period is well documented by institutions like the Bibliothèque nationale de France and other European national archives.