A horse race is a contest of speed between two or more horses, usually in harness and ridden by jockeys or pulled by sulkies driven by drivers. It is one of the world’s oldest sports and has evolved into a complex spectacle involving large fields of runners, sophisticated electronic monitoring equipment, and immense sums of money. The basic concept, however, remains the same: the horse that crosses the finish line first is the winner.

The exact origin of horse racing is not known, although chariot and mounted (bareback) races were well-organized public entertainments in the ancient world. The sport probably arose from challenges between tribes, and early racing was often a training exercise for military horses. The earliest recorded races were in China and Persia in c. 1500 bce, and the sport was later popular in Europe.

Modern racing is a huge industry that involves millions of people and involves enormous sums of money. It is a form of gambling, and some races are held exclusively for that purpose. In other cases, the winner is determined by a system of handicapping, in which a horse’s performance and current form are taken into account. The goal is to make all the horses competing in a given race as evenly matched as possible.

Horse races are usually governed by laws regulating their structure and operation. These may include regulations concerning the type of horses that can participate, the size of the field, and the time limits in which a race must be completed. In some instances, the rules of a particular race may be determined by local authorities or a national governing body.

Some important horse races have shaped the course of history. For example, the Carlisle Bell, an important five-horse race over a distance of just over two miles, was established in 1752 and is “in many ways the most historically significant race of the colonial era,” according to a prominent racing historian. Its flamboyant promoter, Sir William Byrd, was determined to show off his new Thoroughbred and to make a big wager, and he succeeded spectacularly.

Other important races include the Kentucky Derby, Preakness Stakes, Belmont Stakes, and Breeders’ Cup Classics. In addition to these major events, there are many other smaller horse races in the United States and throughout the world.

The most common type of horse race is the flat race, in which a track is paved with smooth and level dirt or turf. The track is typically oval or polygonal in shape and has a long straightaway with a slight curve at the end. Various types of fences, called obstacles, can be used to vary the track’s difficulty, and some horse races are run over hurdles or steeplechases. A European jumps horse tends to start in National Hunt flat races as a juvenile, then move on to hurdling and, finally, if deemed capable, to steeplechasing. The length of a flat race can range from a few miles to six or more.