Dancing Plague of 1518
In July 1518, a woman began suddenly dancing on the streets. Within a month, 400 others had joined her—and nobody could stop. Many died from exhaustion. It is thought that the phenomenon was caused by mass hysteria, or an act to please divine powers, but no definite conclusions have ever been reached.
King Arthur
One of history's most disputed figures was King Arthur, who was said to have led the defense of Britain against Saxon invaders in the late 5th and early 6th centuries. The details of Arthur's existence are based on folklore and legend; historians agree that Arthur most likely did not exist. Regardless, Arthur's mythic power only grew stronger with each passing century.