She turned about her milk-white steed,
And took True Thomas up behind,
And aye wheneer her bridle rang,
The steed flew swifter than the wind.
“Thomas the Rhymer A” Child 37
|The horse she rode on was dapple gray,
And in her hand she held bells nine;
I thought I heard this fair lady say
These fair siller bells they should a’ be mine.
“Thomas the Rhymer B” Child 37
In the first branch or tale of the medieval Welsh mabinogi Pwyll Pendeuic Dyfed, Pwyll and his retinue, desiring to see a marvel (rywedawt), sit on the mound or gorsedd of Arberth, where he in fact does see a marvel:
As they were sitting, they saw a woman mounted on a great, majestic pale-white horse, dressed in brilliant gold silk brocade, coming along the main road that ran past the mound. To anyone who saw it, the horse appeared to have a slow, steady gait as it came even with the mound (Ford, Patrick K, trans. The Mabinogi and Other Medieval Welsh Tales. Berkeley: University of California Press, 1977. 42).
Ac wal y bydynt yn eisted, wynt a welynt gwreic ar uarch canwelw mawr aruchel, a gwisc eureit, llathreit, o bali amdanei, yn dyout ar hyt y prifford a gerdei heb law yr orssed. Kerdet araf, guastat oed gan y march ar uryt y neb a’y guelei, ac yn dyuot y ogyuuch a’r orssed (PKM 9; PPD ll. 203–07).
For three days, no matter how they try, neither Pwyll nor his followers are able to catch up to the woman, despite riding Pwyll’s fastest horses (Ford 1977, 43–44).
This is neither a normal horse, nor a normal rider. The horse is described as “uarch canwelw mawr aruchel,” that is, a pale white horse. A pale horse, usually white or gray, is typical for an otherworld mount (Ford, 1977, 8). The inability of Pwyll and the other men to keep up with the woman, never mind overtake her and her otherworldly horse, is reminiscent of other otherworldly animals and psychopomps, like the magnificent white hinds of Breton lais like Graelent, or like the the otheworldy horse Arawn, the king of the Welsh otherworld, rides when he meets Pwyll in the first part of the same text:
Pwyll Prince of Dyfed, is hunting at dawn in Glyn Cuch. He has released his hounds ahead of him when he is separated from his companions. Pwyll hears first his own pack, and then another pack coming towards his and answering them. At the edge of a level clearing he sees a pack of unfamiliar, white, red-eared dogs bring down a stag.
Despite the strange appearance of the dogs, Pwyll drives them off the stag in favor of his own pack. While Pwyll’s dogs are feeding, a stranger rides up.
As he was feeding the dogs, he saw a horseman coming up behind the pack on a large dapple-gray horse, a hunting horn about his neck, wearing a pale grey garment for hunting gear (Ford 1977, 37).
Ac ual y byd yn llithiau y cwn, ef a welei uarchauc yn dyuot yn ol yr erchwys y ar uarch erchlas mawr; a chorn canu am y uynwgyl, a gwisc o urethyn llwyt tei amdanaw yn wisc hela (PKM 2; PPD ll. 25–27).
The stranger’s horse (later we learn he is Arawn, lord of the Welsh otherworld) is described as erchlas a compound formed of erch “speckled, dappled” and glas (GPC glas). Welsh erch is cognate with Irish erc 2 “speckled, also dark red” (DIL erc).
Spots, dappling or speckling, like gray and white, are otherworld markers (Tymoczko 1981, 87) in medieval Celtic narratives (Welsh 1989, 24). Welsh and Irish each contain two words for gray, one of which (glas in both languages) refers to a color spectrum from dark blue-gray through sea-green to a pale foggy tint. The GPC entry for glas offers “light blue, pale blue, pale green, grayish-blue, slate-coloured,” and cites glas being used to mean “transparent,” when, for instance, the color is applied to rain. The Indo-European root for glas is *ghel-, the root which gives us a variety of words in English that relate to shiny things (glint, gleam, glitter) and glass, as well as a range of yellow-ish things, like gold and gall (AHD *ghel), again, connoting a bright, shifting, shining effect. While Glas describes a shifting tonality associated with liminal states, the other gray (in Welsh llwyd, in Irish liath) is typically used to describe hair or beard color (Coe 1989). Gray, neither black nor white, the color of dusk and pre-dawn, is, like dapples and speckles, a liminal coloration, neither one thing or the other, located in the area between two colors.
Sioned Davies points out that “‘fairies riding white horses’ is an international motif”—which in fact it is, specifically FF241.1.1.1 in the Stith Thompson motif index (Davies, Sioned and Nerys Ann Jones Eds. The Horse in Celtic Culture. Cardiff: University of Wales Press, 1997. 126). Ballads and romances are filled with otherworld folk favoring white horses; in Sir Orfeo, the fairy king is accompanied by otherworld knights “al on snowe-white stedes” (l. 144). There are some really interesting things about this white/gray/dappled horse obsession. First, unless the horse is a true albino, born without any pigment, it isn’t a white horse, it’s a gray horse. Mostly such horse are born dark, and get lighter as they age. There are lots of specific breeds known for this color shift—Icelandic horses (ponies, for those counting hands), for instances, and the horses from the Camargue, and the Connemara ponies, too.
Nature Genetics July 20, 2008 has published an article by Leif Andersson of Uppsala University, parto of a collaborative resarch team whose research indicates that gray or “white” hair coloring is caused by a single, unique genetic mutation. The research suggests that this mutation must have been inherited from a common ancestor that lived thousands of years ago. Andersson says in this Science Daily summary:
It is a fascinating thought that once upon a time a horse was born that turned grey and subsequently white and the people that observed it were so fascinated by its spectacular appearance that they used the horse for breeding so that the mutation could be transmitted from generation to generation.
The original article points out that the mutation is closely tied to cancer, and suggests that humans almost certainly interceded to encourage the mutation: “The Gray horse provides a notable example of how humans have cherry-picked mutations with favorable phenotypic effects in domestic animals.” The Nature Genetics piece is here.