Unicorn Theory in Early Modern Europe

‘Whether there bee a Unicorn? For that is the maine question to be resolved’.

Edward Topsell, The Historie of Foure-Footed Beastes (London, 1607), p. 71.[1]

Caspar Bartholin, Opuscula quatour singularia: I. De unicornu eiusq[ue] affinibus & succedaneis (Copenhagen, 1628), title page.

Early modern treatises on unicorns invariably surveyed the ancient and biblical sources for evidence of their existence and these were not hard to find. Worth owned a copy of Pliny’s Natural History, which described what a unicorn looked like, and Pliny was not alone in the ancient world in drawing attention to these one-horned beasts. Aristotle too could be cited, although his focus had been on the Indian ass and the oryx.[2] Early modern scholars could also point to considerable biblical support for the existence of unicorns. Conrad Gessner (1516-1565), in his seminal Historiae animalium, initially printed at Zurich as a multi-volume work between 1551 and 1558, and bought by Worth in a Frankfurt edition of 1620, was at pains to give chapter and verse. He cites Psalm 92, verse 10 where David announced ‘But my horn shalt thou exalt like the horn of an unicorn’. Equally Deuteronomy 33 and Isaiah chapter 34 also contained references to ‘unicorns’. As Edward Topsell noted in his synopsis of Gessner’s magisterial work, this scriptural underpinning lent strength to the idea of unicorns since, ‘God himself must needs be traduced, if there be no Unicorne in the world’.[3]

However, Gessner was also aware that the biblical support for unicorn ultimately rested on a choice of translation, a decision by the translators of the Greek Septuagint to equate the Hebrew ‘re’em’ with the word ‘unicorn’.[4] The Latin Vulgate of St. Jerome had followed their lead and in turn the King James Authorized Version had included the term ‘unicorn’ wherever ‘re’em’ was found (eight times in the Bible). More modern translators prefer to equate ‘re’em’ with wild oxen (aurochs), rather than the mythical unicorn. That early modern writers such as Gessner were aware of possible linguistic confusion may be seen in his inclusion of an assertion of his contemporary, Pierre Belon (1517-1564), that ‘he knewe the tooth of some certain Beast, in time past, sold for the horne of a Unicorne’.[5] Gessner continues to report that ‘in the new Islands there was a Horne in the name of a Unicornes horne, being much praised for expelling of poison: which what it is I have not as yet examined, but it is to bee inquired, whether it bee a Rhynoceros or not, for both the auncient and late Writers doe mingle this with the Unicorne’.[6] However, as Topsell’s exploration of ‘The medicines arising from the Unicorne’ demonstrates, although he recognised that rhinoceros horn might be passed off as unicorn horn, he still retained a belief in the latter’s medicinal efficacy:

The hornes of Unicorns, especially that which is brought from new Islands, being beaten and drunk in water, doth wonderfully help against poisons: as of late experience doth manifest unto us a man, who having taken poison and beginning to swell was preserved by this remedy. I my selfe have heard of a man worthy to be believed, that having eaten a poison’d cherry, and perceiving his belly to swell, he cured himself by the marrow of this horne being drunke in wine in very short space.[7]

As Brian Ogilvy has noted, for Gessner the eyewitness account of a trusted source was acceptable if personal testimony was impossible.[8] However, it is clear that Topsell had some doubts about the general lore of the unicorn for though he reports that ‘It is sayd that Unicorns above all creatures, doe reverence Virgines and young Maides, and that many times at the sight of them they growe tame, and come and sleepe beside them’ he goes on to recount how the unicorn could be hoodwinked by the use of a decoy, ‘a goodly strong and beautiful young man’ who, it was said, Indian and Ethiopian hunters ‘dresse in the apparel of a woman’ – a stratagem that he reported had some success, but which rather undercut the whole symbiotic lore of the virgin maid and the unicorn.[9]

Thomas Bartholin, De unicornu observationes novae (Amsterdam, 1678), engraved title page.

Worth owned two treatises which were specifically devoted to the study of unicorns. The first was by Caspar Bartholin the Elder (1585-1629), a famous Danish physician and the second by his son Thomas Bartholin (1616-1680), an even more illustrious Danish doctor. Both were famous anatomists, Caspar the Elder being the first to describe the olfactory nerve, and his son Thomas the lymphatic system. The fact that both were medical doctors reminds us of the vital role played by physicians in the exploration of natural history in the early modern period. Likewise, both would also have been attracted to the subject of unicorns because of the medicinal uses ascribed to unicorn horns. Caspar, a leading light of the University of Copenhagen, published his De unicornu eiusq[ue] affinibus & succedaneis (Copenhagen, 1628), a year before his death. In it he identified ‘unicorn’ horns and narwhal tusks as being the horns of two separate one-horned animals.[10] Caspar’s text did not limit itself to the mythic unicorn but instead examined as many one-horned beasts as possible. Thomas’ text went much further – indeed Shepard states that it is ‘the most extensive and impressive work ever devoted to the unicorn’.[11] We can get some indication of this from the engraved title page which depicts a number of different types of unicorn.

Building on the work of both his father and that of his uncle, Ole Worm (1588-1654), another Danish physician and natural historian, who had argued in 1638 that ‘unicorn horns’ were in fact narwhal tusks, Thomas’ treatise, De unicornu observationes novae, undermined the mythic unicorn by debunking the notion of the magical use of its horn. His book was initially published at Padua in 1645 when Thomas was on his peregrinatio academica and it was very much an act of homage to his father. Worth owned the enlarged second edition of 1678, produced by Thomas’ son, Caspar Bartholin the Younger (1655-1738), another medical practitioner of this famous medical dynasty.

However, although Thomas Bartholin made it clear that he did not hold with any medical use for the horns of unicorns, that did not mean that he totally discounted their existence. As the contents of his museum in the Anatomy House of Copenhagen demonstrates, among his many anatomical items were ‘The horn from a Greenland unicorn, three spans long’; ‘A slender horn from a unicorn, also three spans long’; ‘A small horn from a unicorn, one span long’ and, finally ‘A broad fragment of a unicorn’s horn’.[12] These added to the ‘Two unicorn horns, each three spans long’ which had belonged to Bartholin’s cousin, Dr Hendrik Fuiren, whose museum was also located in the Anatomy House.[13]

Georg Caspar Kirchmaier, De basilisco, unicornu, phœnice, behemoth, leviathan, dracone, araneo, tarantula et ave paradisi, dissertationes aliquot (Wittenberg, 1669), title page.

Thomas Bartholin’s work proved to be influential and certainly influenced another text, which may also be found in Worth’s collection: Georg Caspar Kirchmaier’s De basilisco, unicornu, phœnice, behemoth, leviathan, dracone, araneo, tarantula et ave paradisi, dissertationes aliquot (Wittenberg, 1669). This short treatise not only discussed unicorns but also other mythical creatures such as basilisks and other dragons.  Kirchmaier (1635-1700), had studied at the University of Wittenberg and was a scholar whose interests spanned many disciplines: he had been trained there in theology, law, and chymistry, before becoming professor of rhetoric at Wittenberg. A prolific author, he was also a respected member of the seventeenth-century Republic of Letters.

In this small work Kirchmaier turned his attention to the subject of mythical creatures and provided short introductions to some of the most famous. His treatise was initially published as an addendum to John Sperling’s Zoologia physica (Leipzig and Wittenberg, 1661), and Worth bought the second edition of 1669. Sperling (1603-1658), was a colleague of Kirchmaier’s at Wittenberg – in fact he had taught him. His career at Wittenberg had displayed a similar interest in a variety of subjects but Sperling was primarily a physician and became professor of physick in 1634. His Zoologia physica was published posthumously by Kirchmaier and it was probably Kirchmaier’s decision to include his own small tract which focused on a rather different sort of animal.

Kirchmaier makes it clear that in his discussion of unicorns he spread his intellectual net wide. As the sub-headings for his chapter on unicorns demonstrate, he was interested in every kind of animal which might be said to have one horn, and certainly did not limit himself to horses:


  1. Nature and formation of the term Monoceros.
  2. A part of Christ’s Cross is called ‘Unicorn’.
  3. The term applied to a mineral.
  4. Explanation of analogous uses of the word continued.
  5. The existence of unicorn fish.
  6. Unicorn birds seen by the Lusitanians.
  7. The one-honed vipers used by Cleopatra. Cardanus censured.
  8. Single-horned beetles seen by Bartholinus between Salterno and Naples.
  9. The one-horned ass of India.
  10. The one-horned horse presented to the late John George I, Elector of Hanover. Similar creatures seen frequently by other persons.
  11. Single-horned oxen and cows found. To this head the wild oxen of Russia are to be referred.
  12. An account of the wonderful animal called the oryx.
  13. The rhinoceros, the deadly enemy of the elephant.
  14. The rhinoceros not to be confounded with the monoceros. Cardanus blamed and defended. Scaliger praised.
  15. An inquiry into the term unicorn, both as a substantive and as a creature. Various synonyms of the term.[14]

Kirchmaier’s concern was to get at the truth. Having approached the topic from a philological perspective, and surveyed the many different types of one-horned animals in existence, he confessed that he could ‘no longer wonder at the fact that authors nowhere agree with one another in describing the nature of the monceros’.[15] He was well aware that not every commentator believed in the existence of the ‘true’ unicorn. On the other hand, famous scholars such as Scaliger affirmed their existence. Kirchmaier quotes Scaliger as saying that ‘Unicorns are about the size of a horse; they have the head, feet, and legs of a stag, their hair and coat is of a dark chesnut tinge. They have the mane of a horse, though scantier and not so long. Their hips are covered with hair. I have seen a horn of one of these creatures at Nicea, and others at different places. One of these was yellowish, another of a dull tinge, more like the colour of box than anything else. Another was reddish. I have a piece of one in my possession, which is of a white colour’.[16] The academic weight of such an assertion by Scaliger was enormous and Kirchmaier concluded that no one could rationally doubt the existence of a creature which had been referred to by so many varied and trusted sources:

Such being the case, who cares any longer to be of such simplicity or obstinacy as not to hesitate to oppose his own view to so many proofs, both divine and human, for the existence of the unicorn?[17]


Bruun, Niels W., (ed.), Thomas Bartholin: The Anatomy House in Copenhagen briefly described (Copenhagen, 2015).

Gessner, Conrad, Historiae Animalium, 3 vols (Frankfurt, 1620).

Kirchmaier, Georg Caspar, De basilisco, unicornu, phœnice, behemoth, leviathan, dracone, araneo, tarantula et ave paradisi, dissertationes aliquot (Wittenberg, 1669). English translation from Edmund Goldsmid, Un-Natural History or Myths of Ancient Science (Edinburgh, 1886).

Lavers, Chris, The Natural History of Unicorns (London, 2009).

Ogilvy, Brian W., The Science of Describing: Natural History in Renaissance Europe (Chicago, 2006).

Shepard, Odell, The Lore of the Unicorn (New York, 1983).

South, Malcolm, ‘The Unicorn’, in Malcolm South (ed.), Mythical and Fabulous Creatures: A Source Book and Research Guide (New York and London, 1987), pp 5-26.

Topsell, Edward, The Historie of Foure-Footed Beastes (London, 1607).

Wood, Juliette, Fantastic Creatures in Mythology and Folklore: From Medieval Times to the Present Day (London, 2018).

Text: Dr. Elizabethanne Boran, Librarian of the Edward Worth Library, Dublin.

 [1] Topsell’s text is not in the Worth Library but it relied heavily on Conrad Gessner’s Historiae Animalium which Worth had in a three-volume 1620 Frankfurt edition.

[2] Malcom South, ‘The Unicorn’, in Malcolm South (ed.), Mythical and Fabulous Creatures: A Source Book and Research Guide (New York and London, 1987), p. 10.

[3] Topsell, The Historie of Foure-Footed Beastes, p. 712.

[4] Gessner, Historiae Animalium, p. 691.

[5] Ibid., p. 694; Topsell, Historie, p. 716.

[6] Ibid., p. 695; Topsell, Historie, 718.

[7] Ibid., p. 721.

[8] Brian W. Ogilvy, The Science of Describing: Natural History in Renaissance Europe (Chicago, 2006), p. 261.

[9] Topsell, Four Footed Beasts, p. 719.

[10] Juliette Wood, Fantastic Creatures in Mythology and Folklore: From Medieval Times to the Present Day (London, 2018), p. 28.

[11] Odell Shepard, The Lore of the Unicorn (New York, 1983, )p. 176.

[12] Niels W. Brunn (ed.), Thomas Bartholin: The Anatomy House in Copenhagen briefly described (Copenhagen, 2015), p. 119. This is a translation of Thomas Bartholin’s Domus Anatomica Hafniensis brevissime descripta (Copenhagen, 1662).

[13] Ibid., p. 101.

[14] Georg Caspar Kirchmaier, De basilisco, unicornu, phœnice, behemoth, leviathan, dracone, araneo, tarantula et ave paradisi, dissertationes aliquot (Wittenberg, 1669), pp 29-30. English translation from Edmund Goldsmid, Un-Natural History or Myths of Ancient Science (Edinburgh, 1886), p. 51.

[15] Ibid. p. 36 and p. 21 respectively.

[16] Ibid., p. 47 and p. 27 respectively.

[17] Ibid., p. 49 and p. 27 respectively.