Defining the "weirdest" historical fact can be subjective, as different people may find different aspects of history peculiar or surprising. However, here's a historical fact that some might find unusual:
**The Dancing Plague of 1518:**
In the summer of 1518, a bizarre and seemingly inexplicable event occurred in the city of Strasbourg, in what is now modern-day France. A woman named Frau Troffea began dancing fervently in the streets, and this unusual dancing continued for days. What made this incident particularly strange was that Frau Troffea's dancing attracted others, and within a week, around 400 people had joined in the spontaneous dancing.
The "dancing plague" grew to such an extent that local authorities became concerned about public safety. Attempts were made to intervene, and even a stage was constructed to encourage the dancing in the hope that it would end sooner. Medical professionals of the time attributed the phenomenon to a "hot blood" theory, suggesting that the dancers were suffering from a fever that could only be alleviated by dancing.
The dancing plague eventually subsided, but it left a historical mystery. The exact cause of the event remains unclear, with theories ranging from mass hysteria and stress to ergot poisoning (caused by a fungus affecting rye and wheat, similar to LSD). Regardless of the cause, the Dancing Plague of 1518 remains a strange and enigmatic episode in history.