Horse racing is an equestrian sport which has been practiced over the centuries; the chariot races of Roman times are an early example, as is the contest of the steeds of the god Odin and the giant Hrungnir in Norse mythology. It is often inextricably associated with gambling. The common nickname for horse racing is The Sport of Kings.One of the principal forms of horse racing, which is popular in many parts of the world, is Thoroughbred racing. Harness racing is also popular in the eastern United States and more popular than thoroughbred racing in Canada

and parts of Europe. Quarter horse and Arabian racing are also popular in the western United States and Florida.The breeding, training and racing of horses in many countries is now a significant economic activity as, to a greater extent, is the gambling industry which is largely supported by it. Exceptional horses can win millions of dollars and make millions more by providing stud services, such as horse breeding.