Horse racing, sport of running horses at speed, mainly Thoroughbreds with a rider astride or Standardbreds with the horse pulling a conveyance with a driver. These two kinds of racing are called racing on the flat and harness racing, respectively. Some races on the flat—such as steeplechase, point-to-point, and hurdle races—involve jumping. This article is confined to Thoroughbred horse racing on the flat without jumps. Racing on the flat with horses other than Thoroughbreds is described in the article quarter-horse racing.
Horse racing is one of the oldest of all sports, and its basic concept has undergone virtually no change over the centuries. It developed from a primitive contest of speed or stamina between two horses into a spectacle involving large fields of runners, sophisticated electronic monitoring equipment, and immense sums of money, but its essential feature has always been the same: the horse that finishes first is the winner. In the modern era, horse racing developed from a diversion of the leisure class into a huge public-entertainment business. By the first decades of the 21st century, however, the sport’s popularity had shrunk considerably.
Knowledge of the first horse race is lost in prehistory. Both four-hitch chariot and mounted (bareback) races were held in the Olympic Games of Greece over the period 700–40 bce. Horse racing, both of chariots and of mounted riders, was a well-organized public entertainment in the Roman Empire. The history of organized racing in other ancient civilizations is not very firmly established. Presumably, organized racing began in such countries as China, Persia, Arabia, and other countries of the Middle East and in North Africa, where horsemanship early became highly developed. Thence came too the Arabian, Barb, and Turk horses that contributed to the earliest European racing. Such horses became familiar to Europeans during the Crusades (11th–13th century ce), from which they brought those horses back.