Worst outbreak of dancing mania

Tarantism (or choreomania or dancing plague) was first described in the eleventh century, but was particularly prevalent in southern Italy between the 15th and 17th century. Victims were seized by an uncontrollable urge to dance. The worst outbreak was recorded in Aachen, Germany in 1374. This outbreak was named ‘St John’s Dance’, and victims danced for hours until they collapsed with exhaustion. The outbreak spread to other European countries including Belgium and the Netherlands.

Although outbreaks were often framed by mystical or supernatural explanations, there is no doubt that such events took place. The earliest recorded outbreak occurred in 1021 in the German town Kölbigk (though this may have been apocryphal), and many more would occur throughout Europe during the medieval period.

Aside from the Aachen outbreak, the most notable cases of fatal dancing mania occurred in Erfurt in 1247, Trier in 1467 and Strasbourg in 1518. During the latter outbreak, one chronicler recorded that at its peak, 15 people were dying every day as a consequence of dancing themselves to death in the summer heat.

Modern researchers have put forward various theories to explain this strange and now seemingly eradicated disease. This was, after all, not some sort of religious trance – the dancers were apparently acting very much against their will, screaming and begging for mercy as they danced. Some have suggested ergot poisoning (ergot is a fungus that can cause hallucinations and spasms), but the appearance of the phenomenon in regions with different crops and climates makes this seem unlikely. Other have suggested toxins from the fungus Claviceps purpurea, which cause hallucinations and spasms.

The most likely explanation, however, is some sort of mass hysteria. Dancing mania generally only broke out in areas with either legends of people being cursed to dance, or previous outbreaks of the disease. Outbreaks also coincided with period of extreme social stress, such as during famines, economic crises, or in the aftermath of outbreaks of bubonic plague.