Greenland Unicorns: The Strange History of Alicorn

This is an abridged version of my article published by the Public Domain Review in 2019 and included in the Selected Essays Vol.VII.

Unicorns are everywhere these days. You can't walk down a high street or enter a gift shop without encountering these rainbow-spangled creatures in some form. They have become a fashionable symbol of fantasy, escapism and - somewhat paradoxically - individuality. Most people, of course, are well aware that unicorns do not exist.

In the seventeenth century, however, their existence was a serious matter of contention. What was at stake was far more than fantasy: the unicorn underpinned a body of scholarly literature and a lucrative international trade in pharmaceuticals. That trade took a decisive turn in the mid-seventeenth century, when a group of Scandinavian scholars began to examine the unicorn and its purported powers more closely.

At the centre of this shift was Thomas Bartholin’s De Unicornu Observationes Novae (1645; second edition 1678). Quite counter to Bartholin’s intentions, this work helped to move the unicorn from credible reality into myth. His aim was not to dismiss unicorns, but to define them more precisely—and, crucially, to demonstrate that not every horned creature could be called a unicorn.

The history of unicorn and alicorn

By the seventeenth century, unicorns already had a long and varied history. Classical authors such as Ctesias, Aelian, Aristotle and Pliny had described a range of one-horned creatures, from rhinoceros-like beasts to vividly coloured antelope. Ctesias, for instance, wrote of wild asses in India “as large as horses”, with white bodies, dark red heads and blue eyes, bearing a single horn said to protect against poison.

These diverse creatures were transformed in the Middle Ages into a more familiar image: a wild, one-horned horse that could be captured only by a virgin. Bestiaries and texts such as the Physiologus elaborated these stories, embedding the unicorn within Christian symbolism. The animal’s submission to the virgin came to represent Christ’s sacrifice, while its horn—“alicorn”—was believed to purify poisoned water and cure all diseases.

Alicorn was therefore highly prized: an aphrodisiac and a panacea for ailments ranging from fever to the debilities of old age. Nobles owned cups made from unicorn horn to guard against assassination, and apothecaries displayed horns or unicorn imagery to signal access to these potent substances. By the early modern period, the trade in alicorn was thriving, supported by classical authority, Biblical associations and ongoing scholarly endorsement.

Monoceros, Aberdeen Bestiary (Ms 24, folio 15r), written and illuminated in England around 1200

Alicorn from the Arctic

In practice, however, much of this “unicorn horn” came from the far north.

The spiralling tusks of narwhals - strange, little-known marine animals - were widely traded and identified as alicorn. Walrus ivory and elephant tusk were also sold under the same name. As long as the substance was rare and exotic, it was valuable, and its precise origin was difficult to verify. Some apothecaries claimed to distinguish between ivories, noting that narwhal horn was denser and more finely textured, but once ground into powder, such distinctions became largely irrelevant.

This ambiguity did not go entirely unchallenged. The French physician Ambroise Paré expressed doubts about the medicinal properties of unicorn horn, and Arctic exploration in the late sixteenth century began to reveal the narwhal as a likely source. William Baffin’s descriptions of the animal raised awkward questions: if alicorn came from a marine creature rather than a terrestrial unicorn, could it really possess the powers attributed to it?

The Bartholins and the “sea-unicorn”

It was this problem that occupied the Danish scholars Caspar Bartholin, Ole Worm and Thomas Bartholin.

Caspar Bartholin, after examining unicorn horns in European collections, concluded that they could not have come from terrestrial animals. Ole Worm went further, comparing narwhal skeletons with the tusks sold as alicorn and demonstrating that they were one and the same.

Thomas Bartholin sought to resolve the resulting contradictions. In De unicornu, he examined all manner of horned creatures - from rhinoceroses to horned vipers - in order to establish that the presence of a single horn did not in itself define a unicorn. At the same time, he attempted to preserve belief in alicorn by relocating the “true” unicorn.

Rather than a horse-like creature from the East, Bartholin argued, the medicinal unicorn was an aquatic animal from the North. Drawing on Old Icelandic texts such as the King’s Mirror, he presented the inhabitants of the Arctic as long familiar with these creatures and their valuable horns. By invoking northern traditions, he provided the authority needed to support this reinterpretation.

Bartholin also carried out experiments to reaffirm the efficacy of unicorn horn, claiming it could treat illness and even halt epidemics. In doing so, he maintained the medicinal reputation of alicorn while aligning it with the narwhal.

Unicorn, 'Magdeburg unicorn' and narwhal side by side, from Michael Bernhard Valentini’s Museum Museorum (1704)

A brief life of the Greenland unicorn

For a time, this “Greenland unicorn” flourished. The spiralling tusks retained their aura of potency, now supported by both ancient texts and contemporary observation. The unicorn had not vanished, but changed form—from a terrestrial beast of distant eastern lands to a marine creature of the Arctic.

This transformation sustained a profitable trade and allowed scholars to reconcile conflicting evidence without abandoning the idea of the unicorn altogether.

But it was short-lived. By the early eighteenth century, experimental approaches to medicine began to erode confidence in alicorn. Its supposed powers proved unreliable, and its association with marine animals diminished its allure. Carl Linnaeus would later reject the unicorn as a real creature in his Systema Naturae (1735), though the narwhal retained the name Unicornu groenlandicus.

Narwhal tusk, 1701-1930

What happened to the unicorn?

The unicorn’s disappearance from natural history was not simply a matter of error corrected by observation. It reflects a broader shift in how animals were understood.

The unicorn had never been a single, stable creature. It was assembled from classical texts, medieval symbolism, traded objects and scholarly interpretation. Its form shifted across time, shaped by changing expectations and intellectual frameworks.

For a brief period in the seventeenth century, unicorns existed in both land and sea, sustained by a combination of tradition, commerce and experiment. When that balance could no longer be maintained, the creature retreated into the realm of fable.

The processes that sustained it, however - the assembling of animals from fragments, and the investment of those animals with meaning - continued.

Licorne de mer (sea unicorn) and a narwhal depicted as two distinct animals, from Pierre Pomet’s Histoire générale des drogues (1694)

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Read the full essay at Public Domain Review or see some of my other essays on early modern creatures.

If you enjoyed this, do check out my latest book, Enchanted Creatures: Our Monsters and their Meanings as well as my other writing.

Unicorn Alicorn History -- Copyright Natalie Lawrence 2026