Marco Polo found real unicorns, and they turned out to be ugly rhinoceroses
Greek naturalists were sure unicorns lived in India. Medieval Europeans paid fortunes for their horns. Marco Polo went looking and described a mud-wallowing, boar-headed brute that was plainly a rhino. The prized horns were narwhal tusks, yet fake unicorn powder was still sold as medicine in 1741.
The oldest candidate is a one-horned, cow-like animal that is the most common image on soapstone seals of the Indus Valley civilization, from around 2000 BC. It usually faces an object that may be an incense burner, an offering stand or a manger. Small terracotta figures, probably toys, rule out the idea that the carvers simply drew a two-horned bull in profile. Whether that image is really a unicorn remains controversial, and the archaeologist Jonathan Mark Kenoyer sees no direct link to later legends.
For the Greeks, unicorns belonged to natural history, not myth. Ctesias, writing from Persia, described swift wild asses in India with a horn a cubit and a half long, coloured white, red and black, and meat too bitter to eat. Pliny the Elder added a fierce monoceros with a stag's head, elephant's feet and a boar's tail. The 6th-century traveller Cosmas Indicopleustes reported the claim that a hunted unicorn could leap off a cliff and land on its horn unharmed.
Christian allegory transformed the beast. The late-antique Physiologus told of a unicorn that could be caught only by a maiden, laying its head in her lap and falling asleep, an image read as the Incarnation with the maiden standing for the Virgin Mary. Courtly poets such as Thibaut of Champagne turned it into a lover drawn to his lady, and Renaissance artists used it for chaste marriage: Piero della Francesca painted a pair of unicorns pulling a triumphal car. After the Council of Trent, the theologian Molanus condemned it and it largely vanished from religious art.
The horn, called alicorn, was believed to purify poisoned water and cure disease, so royal cups were carved from what was usually elephant or walrus ivory. In 1638 the Danish physician Ole Worm showed that alleged alicorns were narwhal tusks, and Thomas Browne mocked the whole belief in 1646. In the 21st century the unicorn has become an LGBTQ symbol.
Source: Unicorn
