A Brief Summary on the Monoceridae Family and its Domesticated Subspecies
The Monoceridae family, placed within the Pecora infraorder, are defined as even-toed hoofed mammals with ruminant digestion, and are easily identified by their prominent cranial appendages. These unique and distinctive horns have lead the two extant species remaining within this family to both be colloquially known as Unicorns.
Exhibit 1a - Eurasian Unicorn
Exhibit 1a contains an artistic depiction of the Eurasian Unicorn, one of two extant species. In spite of the historic region of the Eurasian Unicorn containing the forest regions of Northern Europe and the Western Siberian hemi-boreal forests, most of this historic range has been lost and the species is declared extinct in Russia, the UK and Scandinavia. The IUCN estimates that remaining numbers of wild Eurasian Unicorns stand at approximately 1400. Most of the remaining population are limited to protected areas of the Schwarzwald forest, though unsubstantiated sightings have been spotted in Poland, Czechia and France.
Exhibit 1b - North American Unicorn (mare and foal).
North American Unicorns differ from their cousins in being adapted to survive the mountainous and desert regions of North America. Unicorns are observed to be attentive parents - juvenile N.A. Unicorns bear dappled coats that help them camouflage against bare rock and scrub flora, which is shed when maturity is reached.
Likewise to it's cousin, N.A. Unicorns are also considered Critically Endangered, with numbers estimated at approximately 2,100, limited almost exclusively to the mountainous regions of Arizona. Human-projected properties of the horn itself has been identified as the biggest threat to both species - historically Unicorns associated with human virtues such as "nobility" and "purity" and were even considered to be "magical" in property; as such, consuming or possessing a Unicorn was said to cure medical malaise or bring good fortune or wealth to a bearer. Medical benefits of Unicorn horn consumption has yet to be validated by modern science.
Domestication of Unicorns
2a - "Abjohn", a Domesticated Unicorn Buck
Despite records indicating that Unicorns were attempted to be domesticated from the Roman period, such attempts were predominantly unsuccessful, with many Unicorns appearing "stubborn" or uncooperative with training. In spite of this, many European Courts kept Eurasian Unicorns as part of Royal Menageries as symbols of wealth and power.
In the 1600s, a buck named Abjohn was born with unusual markings to a mare then owned by Elizabeth the 1st of England - these markings are now understood to be leucism. Being born alongside English naval victory against the Spanish Armada, the birth of Abjohn was considered a mark of divine blessing. Many foals were made to be sired by Abjohn in order to replicate his white markings, which quickly became a desirable feature for domesticated Unicorns. Abjohn is thus considered the "father" of the domestic Unicorn.
2b - Miniature Domesticated Unicorn
As breeding initiatives with Unicorns continued over several hundred years, two standardised breeds were established.
The Miniature Unicorn, in addition to its stature, became desirable due to its docile and agreeable temperament, and became a fixture in courts containing young children, or served as companion animals to jesters or court dwarfs in entertaining monarchs.
Many veterinary experts have argued that the "docile" demeanour of miniature Unicorns is due to multiple hereditary health conditions, including arthritis, angular limb deformities, patellar luxation and dystocia. This has been heavily disavowed by notable breeders; in spite of this, no medical history records of the Miniature Unicorn have ever been made publicly available.
2c - "Gaëlle", a Standard Domesticated Unicorn
Over several hundred years, secondary qualities that were "essential" to breed standard were established and bred into the second standardised breed of Unicorn, the Standard Unicorn. These qualities included a straight, thin horn, a long tail, and qualities generally associated with Equines, including a larger size, longer legs, and a "saddle" back that allowed Unicorns to be ridden or used to play Polo. Ownership is highly exclusive - it has been noted that Standard Unicorns have been sold illegally on the exotic pet trade, with animals being confiscated in locations including Belarus and Nebraska. Whilst there are no recorded total number of Standard Unicorn, it is estimated the number of them doubles the populations of North American and Eurasian Unicorns.
One of the most famous historic Standard Unicorns was Gaëlle, owned by King Louis XVI in his Versaille Menagerie. Admired for her beauty and subject to dozens of paintings, the animal herself was considered controversial due to her aggressive temperament and history of causing physical injury to humans numbering in the dozens, and was never visited by Louis XVI himself. The animal was retired to stable-only residence after an incident where she fatally gored a visiting noble. During the French Revolution, many animals of the declining menagerie were sold or eaten - the fate of Gaëlle, if recorded, is unknown.