of war horses as light and heavy cavalry. The horse played an important role throughout human history all over the world, both in warfare and in peaceful pursuits such as transportation, trade and agriculture. Horses lived in North America, but died out at the end of the Ice Age. Horses were brought back to North America by European explorers, beginning with the second voyage of Columbus in 1493.<ref>Bennett, Deb (1998) 'Conquerors: The Roots of New World Horsemanship. Amigo Publications Inc; 1st edition. , p. 151</ref> Equestrianism was introduced in the 1900 Summer Olympics as an Olympic sport with jumping events. Horse racing Humans appear to have long expressed a desire to know which horse or horses were the fastest, and horse racing has ancient roots. Gambling on horse races appears to go hand-in hand with racing and has a long history as well. Thoroughbreds have the pre-eminent reputation as a racing breed, but other breeds also race. Types of horse racing Under saddle: Thoroughbred horse racing is the most popular form worldwide. In the UK, it is known as flat racing and is governed by the Jockey Club in the United Kingdom. In the US, horse racing is governed by The Jockey Club. other light breeds are also raced worldwide. Steeplechasing involves racing on a track where the horses also jump over obstacles. It is most common in the UK, where it is also called National Hunt racing. In harness: Both light and heavy breeds as well as ponies are raced in harness with a sulky or racing bike. The Standardbred dominates the sport in both trotting and pacing varieties. The United States Trotting Association organizes harness racing in the United States. Harness racing is also found throughout Europe, New Zealand and Australia. Distance racing: Endurance riding, takes place over a given, measured distance and the horses have an even start. Top level races are usually , over mountainous or other natural terrain, with scheduled stops to take the horses' vital signs, check soundness and verify that the horse is fit to continue. The first horse to finish and be confirmed by the veterinarian as fit to continue is the winner. Limited distance rides of about are offered to newcomers. Variants include Ride and Tie and various forms of long riding. International and Olympic disciplines Equestrian events were first included in the modern Olympic Games in 1900. By 1912, all