The term Thoroughbred describes a breed of horse whose ancestry traces back to three foundation sires: the Darley Arabian, the Godolphin Arabian and the Byerly Turk. Named for their owners, Thomas Darley, Lord Godolphin and Captain Robert Byerly, these three stallions were brought to England from the Middle East at the turn of the 17th century and bred to the stronger but less precocious native horse.  This produced an animal that could carry weight with sustained speed over extended distances, qualities that brought a new dimension to the burgeoning, aristocratically supported sport of horseracing.

 

Thus began the selective breeding process that has been ongoing for more than 300 years, breeding the best stallions to the best mares with the proof of excellence demonstrated on the racecourse. 

 

The New World adopted the pastime quickly. Records on Long Island reach back to 1665. However, the introduction of organized Thoroughbred racing is credited to Governor Samuel Ogle of Maryland who encouraged racing between pedigreed horses in the English style. This was first staged at Annapolis in 1745.  As the country grew so did Thoroughbred racing, spreading across the nation from coast to coast. Today, the volume of racing in America far outweighs any other country in the world.

 

In the early days of the Thoroughbred, breeding records were sparse and often incomplete. It was left to Englishman James Weatherby, whose family served as accountants to the members of the Jockey Club (est. 1750), to assume the task of tracing the pedigree - a complete family history of every horse racing in England. Racing’s best formed The Jockey Club, which to this day exercises complete control over English racing. In 1791, the results of Weatherby’s research were published as the Introduction to the General Stud Book, listing the pedigrees of 387 mares, each of which could be traced to Eclipse, a direct descendant of the Darley Arabian, Matchem, a grandson of the Godolphin Arabian, and Herod, whose great-grandsire was the Byerly Turk. From 1793 to the present day, members of the Weatherby family have recorded the pedigree of every foal born to those racehorses in subsequent volumes of the General Stud Book. By the early 1800s, the only horses that could be called "Thoroughbreds" and allowed to race were those descended from horses listed in the General Stud Book, which to this day continues to be published by Weatherby and Sons, Secretaries to the English Jockey Club.

 

Colonel Sanders D. Bruce, a Kentuckian who had spent a lifetime researching pedigrees of American Thoroughbreds, published the first volume of the American Stud Book in 1873. Bruce produced six volumes of the register until 1896 when the project was taken over by The Jockey Club. The integrity of the American Stud Book is the foundation upon which Thoroughbred racing in North America depends. The Jockey Club also took steps to regulate the breeding of racehorses.

 

When The Jockey Club published its first volume of The Stud Book, the registered foal crop was about 3,000. By 1896, it exceeded 51,000. Today, The Jockey Club manages one of the most sophisticated computer operations in the country.[1] This database holds the names of over 2 million horses, names that trace back to the late 1800s. The system also handles the results of every race in North America, as well as pedigree and racing data from England, Ireland, France and other countries worldwide.

 

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[1] The Jockey Club Fact Book

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