The most common theory holds that the idea of centaurs came from the first reaction of a non-riding culture, as in the Minoan Aegean world, to nomads who were mounted on horses. The theory suggests that such riders would appear as half-man, half-animal Horse taming and horseback culture arose first in the southern steppe grasslands of Central Asia, perhaps approximately in modern Kazakhstan.
Centaur carrying off a nymph (1892) by Laurent Marqueste (Tuileries Garden, Paris)
Of the various Classical Greek authors who mentioned centaurs, Pindar was the first who describes undoubtedly a combined monster.