Oh, Bucephalus. I challenge anyone to find me a better archetype for the untamable black stallion fantasy that so many equestrians — myself included — hold deep within their hearts.

It’s intriguing that the Wikipedia contributors who wrote and edited the article on the Bucephalus brand settled on Hammond’s 1998 book The Genius of Alexander the Great as the definitive explanation of Bucephalus’ name, when -- despite the reputation of the author -- the book has some methodological pitfalls. In his review, James Williams states:

[Hammond’s] impressive qualifications, however, do not necessarily lead to a valid interpretation of Macedonia's history or Alexander's career. Hammond assumes a much more "tidy" and civilized Macedonia than most scholars of ancient Macedonia accept, and he reverts back to a hagiographical approach to Alexander as "hero" and "genius" that is based on an arbitrary method of source analysis (virtually anything negative comes from an unreliable source) and which has been systematically demolished by the extensive writings of Ernst Badian and A. B. Bosworth...Alexander had bad characteristics-excessive lust for glory, binge drinking, inability to accept powerful subordinates, paranoia, brutality when thwarted, and extreme egocentrism. Hammond serves as a "spin doctor" for these, and he also portrays Macedonia as far too neat, orderly, and constitutional a society.

In another review, Doyne Dawson states:

Hammond has strong views which (as he would readily concede) have not met with universal assent. Ancient writers mention a "Royal Journal" allegedly written at Alexander's court. Many modern scholars think that this document, now lost, was a later forgery. Hammond believes that it was genuine and that it provided the basis for Arrian's Anabasis of Alexander (second century A.D.), an assumption that elevates Arrian to a position of unique authority among the ancient Alexander historians, and makes Hammond more confident than most of his peers about the prospects for reliable reconstruction of Alexander's career and personality.

Hammond’s book, as both reviewers also note, is written for a lay audience, not a scholarly one.

It’s difficult to separate fact from fiction when it comes to Bucephalus. The concept of the wild black stallion who is seemingly telepathically bonded to a single person resonates with people. Indeed the modern incarnation of this archetype, Walter Farley’s Black Stallion series of books, has sold over 73 million copies since the first book was published in 1941. The mythos of Alexander the Great, and by extension the mythos of Bucephalus, coalesced during the 3rd Century AD in the Alexander Romance, a wildly popular genre of medieval literature that embellished the historical exploits of Alexander the Great with fanciful tales of legends, adventure, and mythical beings. Bucephalus in this tale is presented not just as an untamable horse, but a man-eating beast used to mete out capital punishment, and who is tamed by the mere sight of a teenaged Alexander:

When Alexander was fourteen years old, one day he happened to be passing through the district where Bucephalus was confined, and heard a most frightful neighing. And turning to his friends, he said: "Men, is this neighing the roar of a horse, or of a lion?" Ptolemy...who was accompanying him, on being addressed, answered: "This is Bucephalus, whom your father shut up because he is a man-eater." Then the horse, on hearing the voice of Alexander, neighed a second time, making a sound not utterly frightful and mournful, but rather gracious, for a god at once dominated him. And then Bucephalus himself, on seeing Alexander, stretched out his feet before himself and moved his whole body as if offering a prayer to his own ruler.

The most complete descriptions of the historical Bucephalus come largely from the writings of Plutarch and Arrian. Of the two, Plutarch’s depiction of Bucephalus, which contains the story of his taming, is considered the more authentic, although scholars may debate the veracity of the exact details. The fractious stallion was dark: if not black then bay. He had a large star or a blaze on his face. He was purchased for an exorbitant sum of money. And he descended from fine Thessalian stock.

While Bucephalus’ exact parentage is unknown, recent genetics studies can shed light on Thessalian breeding culture. The Thessalian horse was likely the descendant of the steppe horses of Eastern Europe, Turkey, Kazakhstan, and other nearby regions. There was little admixture with horses from the Middle East. The genetic influence of Arabian horses on European stock coincides only with the Byzantine-Sasanian Wars and early Islamic conquests.

Several breeds of horse were produced in Thessaly, and different brands were used to denote the breed of each horse. One of the brands was indeed shaped like an ox’s head. However, it had already become unclear by the 2nd Century AD if the brand was in fact the origin of Bucephalus’ name. In his Anabasis of Alexander, Arrian writes:

The head of an ox had been engraved upon him as a distinguishing mark, and according to some this was the reason that he bore this name; but others say, that though he was black he had a white mark upon his forehead which bore a great resemblance to the head of an ox.

A.R. Anderson, in his 1930 analysis of Bucephalus’ legend, favors the ox-head brand explanation of Bucephalus’ name -- just like the writers and editors of the respective Wikipedia articles do -- hypothesizing from extensive source material that Bucephalus so perfectly typified the ox-head breed that he was given his name as a matter of course. However, unlike on Wikipedia, Anderson acknowledges the competing theories behind Bucephalus’ name, and acknowledges the textual evidence that supports them: Bucephalus’ facial markings could have resembled an ox’s head, or the stallion’s head itself could have been shaped like that of an ox.

The question of why Wikipedia states so certainly that Bucephalus’ name was derived from his brand, even though the extant sources contradict themselves, as well as why the article leans so hard on a fallible source can be seen in the editorial decisions of the article’s contributors. The earliest incarnation of the Wikipedia article on Bucephalus the horse was written by one GilesMoss in 2003. The article continued to be revised and expanded, and by the end of 2004 included a reference to the mythic Bucephalus in the Alexander Romance, who was indeed named for a mark on his haunch shaped like an ox’s head. However, the first statement that the historic Bucephalus was named for the ox-head brand didn’t appear until January 17, 2016. Citing the Hesychius Dictionary, an anonymous editor added:

Αccording to the dictionary of Hesychius ( Ησύχιου ), the Bucephalus (Βουκεφάλας )was not just a name, but a category of Thessalian horses brought a bucrania (ox + skull), ie: an ox head, as a hallmark of Thessaly studs, stamped with red-hot iron on the croup. Therefore this famous horse he owed his name to a croup and not his head.

This addition to the article was altered on February 15 of the same year by the user Andy Smith, providing instead Hammond’s book as the definitive source for the claim. He comments on his decision in the revision history:

Cut down section on naming; link to Bucephalus (brand). Change source and remove unsupported claims – Hesychius's lexicon describes the brand but doesn't mention this horse, or the Thessaly link, unless in notes in the edition previously cited.

This change is derived from the information stated in the Bucephalus brand article. Originally written in 2006, this article did not link the name of the brand to the name of the horse until 2009, when a user going by the handle of Catalographer added the line:

Alexander the Great's horse was named Bucephalus after this brand on its haunch

And sourced it from Hammond’s book.

Wikipedia’s standards for citations likely contributed to the absolutist use of Hammond as a reference. To promote verifiability, the website encourages users to neutrally cite reliable sources. As Wikipedia does not publish original research, articles are supposed to be based largely on secondary sources, leading primary sources to be considered less reliable:

Unless restricted by another policy, primary sources that have been reputably published may be used in Wikipedia, but only with care, because it is easy to misuse them. Any interpretation of primary source material requires a reliable secondary source for that interpretation. A primary source may only be used on Wikipedia to make straightforward, descriptive statements of facts that can be verified by any educated person with access to the primary source but without further, specialized knowledge.

Scholars like Anderson rely on a gamut of sources to craft an argument, but the average Wikipedia editor cannot invoke Plutarch or Arrian or the Etymologicum Magnum in the same way. Nuance of the arguments surrounding a claim can be lost depending on which secondary source a user cites. The story of Bucephalus’ name is a sterling example of this phenomenon. The critical mass of editors of these two articles have fixated on an interpretation of the sources to the arguable detriment of not just scholars who artfully sidestep the mythos and controversy in their work, but those who enjoy tackling every angle head on.

(Sources below)