There are numerous engravings and paintings of Thoroughbred founder sires, but the first portraits of Thoroughbred mares do not appear until the time of Wootton and Stubbs in the mid-18th century.

breed where winning the Derby (either Kentucky or Epsom) is of supreme significance, most of the winners have in fact been stallions. The race may be carried forward in the wombs of broodmares, but at the racetrack, it is usually the stallion who winds up wearing the roses.

The Jockey Club defines a Thoroughbred horse as one who descends from one or more of the following three stallions: Herod (or King Herod), foaled in 1758, a descendant of the Byerley (or Byerly) Turk, 1689; Matchem, foaled 1748, a descendant of the Godolphin Barb, 1724; or Eclipse, foaled 1764, a descendant of the Darley “Arabian,” 1700. The Darley line is today by far the largest, indeed so large that it will take the next two articles in this series to cover it. In those essays, we will see how most of today’s successful Derby winners descend from a single Darleyline subdivision. of stride that eats up distance. Here we find the relatively long cannon bones that set the horse up a little high on its legs. Here is the “flat” muscling and the big, boxy hindquarters with prominent points of hip and long points of buttock that give the breed its powerful racing “motor.” Here are the long, rather narrow heads with thin jowl, fine throatlatch, prominent eye and nostril, and pricked ears; here the long, flat necks with scant crest or mane. Here, too, is the body balance, not level or uphill as in the Jennet or other breeds meant strictly for pleasure-riding, but slightly rump-high, angling just enough downhill from core of loin to base of neck to assure good traction during acceleration for both the hind and fore feet. At the same time, the degree to which the horse’s body balance runs downhill is noticeably less than that in the sprintracer as exemplified by the modern Quarter Horse---a subject we will explore in upcoming installments.

Thoroughbreds were originally valued as horses who could “carry speed over a distance of ground,” the distance in question being much longer than any modern flat-track race, although shorter than the shortest modern Enduro races. In the text above, I have emphasized the importance of the conditions under which horses are raced, which amounts to a specification of the work expected of them as well as a measure of the physical demands