The dancing plague of 1518 was strange in Strasbourg, which was then part of the Holy Roman Empire (now France). In the summer of 1518, Frau Troffea began dancing in the streets and continued for days without rest. Soon, more people joined her, and within a month, around 400 people were dancing uncontrollably in the city.

The dancers appeared trance-like, unable to stop themselves from moving, even when exhausted, injured, or in pain. Reports described them as sweating, convulsing, and sometimes even dying from exhaustion or heart attacks. The outbreak became a public spectacle, attracting curiosity and concern.

To address the situation, local authorities believed that a natural imbalance of bodily humor caused the dancing. They arranged for musicians and professional dancers to accompany the afflicted, hoping that more dancing would eventually tire them out and resolve the issue. Additionally, they opened up public spaces and organized special dance halls to contain the dancers and minimize the disruption to the city.

Medical professionals of the time also proposed various explanations, including ergotism, a condition caused by consuming rye bread contaminated with ergot fungus, which can induce hallucinations and muscle spasms. Other theories suggested mass hysteria, stress, or religious fervor as potential causes.

Eventually, the dancing plague subsided independently, decreasing the number of affected individuals. Over time, the incident was largely forgotten, but it remains a fascinating historical event and has been the subject of various theories and interpretations by scholars and researchers.

It's worth noting that the dancing plague of 1518 was not an isolated incident. Similar outbreaks of dancing mania occurred throughout Europe during the medieval and early modern periods, although none reached the scale and duration of the Strasbourg incident.