In 1374, on the streets of Aachen, people started dancing involuntarily. They moved frantically until near the point of total exhaustion. Within weeks this strange compulsion spread to the Netherlands and north-east of France. Hundreds of people uncontrollably jumped, leapt and twitched for days. This peculiar event was painted by Pieter Brueghel (Dance of Saint Guy). This phenomenon is called dance mania, the dancing plague, or St John's Dance (sometimes St. Vitus' Dance) as it was considered to be a curse sent by a saint. As unbelievable as it seems, it happened repeatedly in the area along the Rhine. Chronicles agree that people were dancing, and not only shaking. But they were obviously suffering from physical pain, too, as well as having horrible visions and sometimes asking for help and praying. Often, they barely ate or slept and sometimes they were not even conscious of what was happening to them.
Present-day researchers believe the bizarre outbreaks were examples of mass psychogenic illness triggered by fear and depression. Both manias (1374 and 1518) were preceded by periods of devastating famine, crop failures and the spread of diseases – tough conditions, even by the standards of the Middle Ages. The anxiety and guilt together with a deep superstition, that God is punishing them for their wrongdoing, made people susceptible to this peculiar involuntary state.