The Darley Arabian (c. 1700–1730) was one of three dominant foundation sires of modern Thoroughbred horse racing bloodstock.

This bay Arabian horse was bought in Aleppo, Syria, by Thomas Darley in 1704 and shipped to Aldby Park in England, as a present for his brother.

By all accounts, the Darley Arabian stood about 15 hands high and was of substantial beauty and refinement.

In 95% of modern Thoroughbred racehorses, the Y chromosome can be traced back to this single stallion.

[5][6] This is mainly through his descendant, Eclipse, who is the direct male ancestor of 95% of all thoroughbreds and in the pedigree of many of the rest.