Origin of the Thoroughbred Horse...

Thoroughbred horse breeding originated in England and the term Thoroughbred describes a breed of horse whose ancestry traces back to three foundation sires;

The three sires are named after their respective owners; Thomas Darley, Lord Godolphin and Captain Robert Byerly.

During the crusades English bred heavy horses were used as they had the strength and stamina to do hard work and carry a man in full armor. However, the lighter horses of the Middle East were bred for their stamina and speed.

The Byerley Turk ...

In 1690 Captain Robert Byerley captured a stallion of mostly Middle Eastern blood.

He rode this stallion through the remainder of the war and then brought it home to England.

He began breeding the horse with the native mares and the horse lived for six more years siring many important horses and becoming the greatest contributor to the Herod line of thoroughbred horse breeding along with Highflyer the son of Herod.

This stallion is entered in the studbooks as Byerly Turk, the last being accidentally omitted.

The Darley Arabian ...

In 1704 Thomas Darley shipped a stallion to England from Aleppo.

He began selectively breeding this stallion to some of the native racing mares and the first great racing horse was born, Flying Childers.

The Darley Arabian was the greatest contributor to Eclipse and ninety percent of all of the registered Thoroughbreds can be traced back to Eclipse.

Godolphin Arabian - The Thoroughbred Horse

The Godolphin Arabian ...

The third foundation sire was the Godolphin Arabian.

He was brought to England in 1728 by Lord Godolphin.

Most of the Matchem line can be attributed to him.

The Thoroughbred Horse

The descendants of these three sires were bred and crossbred to create a horse that was very fast, yet strong. Almost all of the selective breeding was for one purpose, to produce the fastest horse on the track.

  • The thoroughbred has a wide girth for a large lung capacity,
  • Strong legs for hard running.
  • The shoulder is long and sloped to allow a greater stride.
  • The hind leg is long so that it can gain greater ground quickly.
  • Everything about thoroughbred horse breeding builds speed.

The horses were shipped to America almost with the first settlers and Governor Samuel Ogle established racing competitions in Annapolis in 1745.

From then on a selective breeding process began which has been going on for more than 250 years, breeding the best stallions to the best mares, with proof of superiority and excellence established on the race track.

The average height of today's Thoroughbred is a little over 16 hands,

As opposed to the 14-hand average height of the horses from which the thoroughbred breed originated.

But the key word is average, because, for every rule as to what the perfect Thoroughbred should look like, there is a champion whose performance disproves it.

The best guidelines for good conformation come from appreciation of what the body is required to do.

  • Four slender legs must carry more than 1,000 pounds of body weight over extended distances, traveling at speeds of 35-40 miles per hour,
  • Yet still have the strength and suppleness to respond to changes of pace or direction as dictated by racing conditions.

But, although mechanical and engineering formulae can be used to measure the most desirable dimensions and angles of the body's components, there is no way to measure the most important qualities of a Thoroughbred horse -- its courage, determination and will.

If there is one place where these attributes are reflected in the thoroughbred horse, it is the shape and carriage of the head and the look in the eye.

  • The head should be correctly proportioned to the rest of the body, displaying a good flat forehead and wide-set intelligent eyes. Carried relatively low, the head should sit well on a neck which is somewhat longer and lighter than in other breeds.
  • The withers should be high and well-defined, leading to an evenly curved back.
  • The shoulder should be deep, well-muscled and sloped along the same parallel as that on which the head is carried.
  • From the point of the shoulder, the forearm should show adequate muscling which tapers towards a clean-looking knee which in turn tapers into the full width of the cannon. This in turn should be short and comparatively flat, with the tendons distinctly set out and clean.
  • The pastern should be neither too long nor too short and set at an angle a little less than 45 degrees to the vertical.
  • When viewed from behind or in front, the legs should be straight and move smoothly in unison through one plane.

Power comes from the hindquarters and all-important is that the bone structure of the upper hind leg is such that it can make room for long, strong muscling. These driving muscles act between the hip bone and the thigh bone which should be long and the angle it makes with the hip bone wide.

This powerful muscling of the hip and thigh should continue down through the gaskin. And, finally, the trailing edge of the hind cannon should follow a natural perpendicular line to the point of the buttock.

The key to the selective thoroughbred breeding process is the integrity of the breed's records.

In the early days, Thoroughbred breeding records were sparse and frequently incomplete, it being the custom, among other things, not to name a horse until it had proved outstanding ability.

It was left to James Weatherby, through his own research and by consolidation of a number of privately kept pedigree records, to publish the first volume of the General Stud Book.

The Thoroughbred Horse

He did this in 1791, listing the pedigrees of 387 mares, each of which could be traced back to Eclipse, a direct descendent of the Darley Arabian; Matchem, a grandson of the Godolphin Arabian; and Herod, whose great-great grandsire was the Byerly Turk.

The General Stud Book is still published in England by Weatherby and Sons, Secretaries to the English Jockey Club.

Several years later, as racing proliferated in the fast-expanding continent of North America, the need for a pedigree registry of American-bred Thoroughbreds, similar to the General Stud Book, became apparent.

The first volume of The American Stud Book was published in 1873, by Col. Sanders D. Bruce, a Kentuckian who had spent almost a lifetime researching the pedigrees of American Thoroughbreds.

Bruce closely followed the pattern of the first General Stud Book, producing 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 on which all Thoroughbred racing in North America depends.

Without assurance, beyond all reasonable doubt, of the identity of every Thoroughbred which competes, or which is bred with a view to continuing the breed, the sport of racing as it is known today, could not exist.

Nor would there be any possibility of measuring results of the centuries-old quest to improve the Thoroughbred.

When The Jockey Club published its first volume of the Thoroughbred Stud Book the foal crop was about 3,000.

By 1986 it exceeded 51,000 and The Jockey Club embraced new computer technology to meet the registration challenges posed by such large numbers.

Today, The Jockey Club manages one of the most sophisticated computer operations in the country.

The Thoroughbred Horse

Its database holds the names of more than 1.8 million horses on a master pedigree file, names which trace back to the late 1800's.

The system also handles daily results of every Thoroughbred race in North America, as well as processing electronically-transmitted pedigree and racing data from England, Ireland, France and other leading Thoroughbred racing countries around the world.

Further giant strides in improvement of the integrity of the Stud Book came in 1977, when The Jockey Club, taking advantage of medical science advances, took the first steps of an extensive blood-typing program.

Today every Thoroughbred foal registered in The American Stud Book, and its sire and dam, is blood-typed to insure parentage verification.

Guardianship of The American Stud Book is a responsibility of The Jockey Club, almost as old as the very tradition of racing in North America. But its implementation involves some of the most sophisticated developments of the modern technological era.


In 1970, master equine artist, Richard Stone Reeves, was commissioned by the Thoroughbred Record magazine to paint The Perfect Horse.
The Thoroughbred Horse

The resulting composition included the outstanding features of horses like Citation, Buckpasser, Vaguely Noble, Jay Trump and Tiepoletto.

After more than 20 years of painting horses all over the world; wrote Reeves, it took a lot of reflection to pick the best head and neck, the finest shoulder, etc., and, in the end, it all only amounts to one man's opinion.

Reeves' comment aptly describes the enigma of what the perfect Thoroughbred should look like.

Because, in the final analysis, no dictatorial rule can ever define that arrogant yet beautiful coordination of power and fluid action which is a Thoroughbred horse in motion.