Yes, as Laura states distant cousins, as she supports with great links...To add:
Starting in the 1740s and 1750s, some of the most prominent men in Virginia began importing horses from England for breeding and racing. Today, all purebred horses, even the best in thoroughbred racing, can be traced to the same foundation sires that created the great racehorses of eighteenth-century England and Virginia.
A selective breeding process began in England in the early 18th century when Arabian stallions were imported and bred with native English mares. These "foundation" stallions were the Byerly Turk, Darley Arabian, and Goldolphin Arabian. The resulting foals were the start of the Thoroughbred horse.
William Black, a Virginia resident and horse breeder, was very proud of the lineage of his horse Regulus. Black specifically mentions Regulus' connection to his sire Fearnought. Fearnought's sire was the Godolphin Arabian, and his dam was a descendent of the Darley Arabian. In addition, Regulus' dam, Jenny Dismal, was the granddaughter of the Godolphin Arabian. Black wanted anyone interested in breeding their mare to Regulus to know that he had connections to two of the "foundation" Arabians on his sire's side and one on his dam's side.
Besides Regulus' breeding, his own racing record distinguished him as a desirable racehorse to produce fine foals with beauty, size, endurance, and speed. Today, all Thoroughbred racehorses can be traced back to the same foundation sires. It is estimated that over 90% of all racehorses today can trace their bloodlines to the Darley Arabian. For example, the bloodlines of Secretariat, the 1973 Triple Crown Winner, can be traced to the Darley Arabian. And the bloodlines of Seabiscuit, grandson of Man of War and 1937 Triple Crown Winner, can be traced to the Goldophin Arabian. For more information on racehorses and their bloodlines http://www.bloodlines.net/TB/
So, the next time you watch a horse race, think about the long line of tradition and breeding each horse brings to the track!