The unicorn is the legendary one-horned horse of Western imagination — a creature of great purity, grace, and wildness, with a single long horn projecting from its forehead. The legend has been told for more than two thousand years, from the Greek accounts of the Indian wild ass to the modern fantasy novels and films. This page traces the origin and history of the unicorn legend, from the first Greek reports to the modern revival.
Ctesias of Cnidus and the Indian Wild Ass
The earliest known description of a unicorn is in the Indica of Ctesias of Cnidus, a Greek physician at the court of the Persian king Artaxerxes II in the fifth century BCE. Ctesias wrote a book on the wonders of India, drawing on Persian sources and his own observations. In it, he described a wild ass of India, white of body, with red head, blue eyes, and a single straight horn projecting from its forehead. The horn, he said, was a cubit long, white at the base, black in the middle, and crimson at the tip. The horn, he added, could purify poisoned water.
Ctesias’ description is almost certainly a confused account of the Indian rhinoceros, a real one-horned beast known to the Persians and to travelers on the trade routes. The single horn of the rhinoceros, the size and strength of the animal, its untamable nature — all fit Ctesias’ description. But the description was elaborated in the retelling, and the legend grew.
Aristotle, in his Historia Animalium (fourth century BCE), mentioned the monoceros (literally “one horn”) and gave it a single horn projecting from the center of its head. He said the monoceros was the size of a horse, with the foot of an elephant, the tail of a boar, and a single horn a cubit and a half long. Aelian, in his De Natura Animalium (third century CE), described the cartazon (his name for the unicorn) as having the feet of an elephant and a black horn that was sharpest at the tip. Pliny the Elder, in his Natural History (first century CE), repeated the description of Ctesias and added that the unicorn was the fiercest of all beasts, that it could not be caught alive, and that its horn was used for drinking cups that could detect poison.
The Greek description, in short, was a fierce, untamable, one-horned beast of India, the size of a horse or larger. The transformation of this beast into the small, white, horse-like unicorn of the medieval bestiaries was the work of centuries.
The Physiologus and the Medieval Bestiary
The Christian re-interpretation of the unicorn began with the Physiologus, the Greek Christian bestiary of the second or third century CE. The Physiologus was one of the most popular books of the late ancient and early medieval world, translated into Latin, Ethiopic, Syriac, Armenian, Arabic, and many other languages. It was the basis of the medieval bestiary tradition.
The Physiologus said that the unicorn was a small animal, like a young goat, with a single horn. It was so fierce that no hunter could catch it. But a virgin maiden could tame it: the unicorn would lay its head in the virgin’s lap, and the hunters could then take it. The Christian interpretation was immediate: the unicorn was Christ, the virgin was Mary, the hunters were the Jews or the Romans, the slaying of the unicorn was the crucifixion. The single horn, which pierced the side of the sleeping unicorn, was the lance of the Roman soldier Longinus, which pierced the side of Christ on the cross.
This Christian allegory was the dominant form of the unicorn legend throughout the Middle Ages. The unicorn was a symbol of purity, of grace, of the incarnation, of the redemption. The horn of the unicorn — the alicorn — was the most prized of all medieval objects, capable of purifying poisoned water, of detecting lies, of curing disease.
The bestiary description of the unicorn gave it a spiral horn, white at the base, black in the middle, and crimson at the tip (the colors of the Passion of Christ). It was a small, horse-like creature, sometimes with the beard of a goat, sometimes with the cloven hooves of a deer, sometimes with the tail of a lion. It was wild, untamable except by purity, swift as the wind, and dangerous when cornered.
The Unicorn in Heraldry
The unicorn became a prominent figure in European heraldry in the twelfth century. The earliest known appearance of the unicorn in Scottish heraldry is on the seal of William I of Scotland, who reigned from 1165 to 1214. The seal shows a unicorn as the crest, and the unicorn became a symbol of the Scottish crown.
The unicorn became one of the two supporters of the royal arms of Scotland, paired with the lion of England. The two supporters are shown facing the central shield, with the unicorn on the left and the lion on the right (from the viewer’s perspective). The Scottish unicorn is shown with a crown around its neck, attached by a gold chain, indicating that even the unicorn, the wildest of creatures, can be bound by royal authority.
The English royal arms adopted the unicorn as a supporter after the union of the crowns of England and Scotland in 1603 under James I. The combined arms of Great Britain show the lion of England and the unicorn of Scotland as the two supporters, with the motto Dieu et mon droit (“God and my right”) and the Scottish motto Nemo me impune lacessit (“No one provokes me with impunity”) below.
The unicorn in heraldry is shown in various tinctures (colors), but the most common is the silver or white unicorn with a gold horn. It is always shown with a single horn, often with a spiral pattern. The unicorn, in heraldry, stands for purity, grace, nobility, and strength.
The Unicorn Horn Trade
The horn of the unicorn — the alicorn — was the most prized of all medieval objects, and a thriving trade in alleged unicorn horns grew up in the later Middle Ages. The horns were sold by apothecaries as a universal antidote to poison, and they were used in the cups of kings and nobles to detect and neutralize any poison in the wine.
The trade was based largely on narwhal tusks, the long single teeth of the Arctic narwhal, which were traded south from Greenland and Iceland through Scandinavia and the Hanseatic League. The tusks are white, spiraled, and can grow up to nine feet long — they look exactly like the alicorn of legend. The most famous narwhal tusks in the royal collections of Europe were said to be unicorn horns, and the deception was not fully exposed until the seventeenth and eighteenth centuries.
The Danish king Christian III had a cup made of narwhal tusk, said to be a unicorn horn, that was used by the kings of Denmark for centuries. The elector of Saxony Augustus had a similar cup. The emperor Rudolf II of Prague had a famous collection of alicorns, all of which were narwhal tusks. The alicorn, in the form of the narwhal tusk, was one of the great commercial objects of the early modern period.
The trade in alicorns as unicorn horn was a major economic activity of the late medieval and early modern world. The tusks were rare, expensive, and prized. They were given as diplomatic gifts, displayed in the cabinets of wonders of the great princes, and used in the coronation cups of kings. The unicorn, in the form of the narwhal tusk, was a creature of the early modern court as well as of the medieval bestiary.
The Famous Tapestries
The unicorn is celebrated in two of the most famous sets of medieval tapestries in the world. The first is The Lady and the Unicorn (La Dame à la licorne), a set of six tapestries made in Flanders around 1500, now in the Musée de Cluny in Paris. The tapestries show a noble lady with a unicorn, against a background of flowers and trees. Each tapestry bears a motto: “To my only desire” (À mon seul désir). The meaning of the tapestries has been debated for centuries, but they are perhaps the most beautiful representations of the unicorn in Western art.
The second is The Hunt of the Unicorn (La Chasse à la licorne), a set of seven tapestries made in Flanders around 1500, now in the Cloisters of the Metropolitan Museum of Art in New York. The tapestries show the hunt of the unicorn, the capture of the unicorn by a virgin, the killing of the unicorn, the bringing of the unicorn into a castle, and the resurrection of the unicorn from a fountain. The tapestries are in a remarkable state of preservation and are among the most famous works of medieval art in the world.
The Nineteenth Century Revival
The unicorn had a major revival in the nineteenth century, when medievalism became a major cultural force. The seal of Scotland, the Victorian taste for the medieval, the publication of such books as the 1885 The Truth About Unicorns — all contributed to a renewed interest in the creature.
The unicorn appeared in the paintings of the Pre-Raphaelites, in the poetry of Tennyson, in the novels of William Morris, and in countless other nineteenth-century works. The Victorian era was fascinated by the medieval, and the unicorn was one of the great medieval symbols. The seal of Scotland was widely known, and the unicorn was a familiar figure in popular culture.
The unicorn was also the subject of serious scholarly study in the nineteenth century. The publication of the medieval bestiaries, the cataloguing of the unicorn in heraldry, the analysis of the narwhal tusk trade — all contributed to a richer understanding of the legend. The unicorn was no longer just a mythical beast; it was a creature with a history, a literature, and a meaning.
The Twentieth and Twenty-First Century
The unicorn has become even more popular in the twentieth and twenty-first centuries. It is in My Little Pony (the unicorn Twilight Sparkle and many others), in Harry Potter (the unicorns of the Forbidden Forest, the blood of which keeps the wizard Voldemort alive), in The Last Unicorn (Peter S. Beagle’s 1968 novel, with the beautiful unicorn who is the last of her kind), in Fantasia (the white unicorn of the moonlight scene, drawn from the medieval tapestries), and in countless fantasy novels, films, and television series.
The unicorn is, in the modern imagination, the symbol of purity and grace, the beautiful and untamable creature that can be approached only by the pure of heart. It is the magical horse, the symbol of the rare and unique, the noble and solitary beast. The unicorn is on the cover of countless young-adult novels, in the names of countless small businesses, in the logos of countless products. The unicorn has become, in the modern era, a fully naturalized inhabitant of the popular imagination.
The unicorn of the medieval bestiaries, the unicorn of the Scottish royal arms, the unicorn of the Lady and the Unicorn tapestries, the unicorn of My Little Pony — they are all the same creature, in different costumes, in different stories. The legend has been carried forward, in a continuous tradition of telling and re-telling, from the Greek Ctesias to the modern fantasy novel, from the rhinoceros of the Indian trade routes to the magical horse of the modern young-adult novel. The unicorn has been with us for at least two thousand years, and it will be with us for at least two thousand more.
Last reviewed: June 2026.