The earliest evidence for the domestication of the horse comes from Central Asia and dates to approximately 4,000 BCE. Competing theories exist as to the time and place of initial domestication. Wild species continued to survive into historic times. For example, the Forest Horse (Equus ferus silvaticus, also called the Diluvial Horse) is thought to have evolved into Equus ferus germanicus, and may have contributed to the development of the heavy horses of northern Europe, such as Ardennais.

The tarpan, Equus ferus ferus, became extinct in 1880. Its genetic line is lost, but its phenotype has been recreated by a "breeding back" process, in which living domesticated horses with primitive features were repeatedly interbred. Thanks to the efforts of the brothers Lutz Heck (director of the Berlin zoo) and Heinz Heck (director of Tierpark Munich Hellabrunn), the resulting Wild Polish Horse or Konik more closely resembles the tarpan than any other living horse.

Przewalski's Horse (Equus ferus przewalskii), a rare Asian species, is the only true wild horse alive today. Mongolians know it as the taki, while the Kirghiz people call it a kirtag. Small wild breeding populations of this animal exist in Mongolia.