Today's thoroughbreds are a result of more than 300 years of selective breeding that has carried them very far from their roots on the steppes and deserts of the Middle East. Every thoroughbred is descended from one of three stallions, the Darley Arabian, Godolphin, and the Byerly Turk, brought to England toward the close of the 17th century and bred to mares initially under the patronage of King Charles II. A great-great-grandson of the Darley Arabian, bred by a son of King George II, was born during a solar eclipse in 1764 and named Eclipse. An undefeated champion on the track, he sired 344 winners, and his powerful bloodline literally eclipsed all others. In fact, 95 percent of the thoroughbreds alive today are his descendants.