The Arabian Art of Taming and Training Wild and Vicious Horses

...The first domestication of the horse, one of the greatest achievements of man in the animal kingdom, was not the work of a day; but like all other great accomplishments, was brought about by a gradual process of discoveries and experiments. He first subdued the more subordinate animals, on account of their being easily caught and tamed, and used for many years the mere drudges, the ox, the ass, and the camel, instead of the fleet and elegant horse. This noble animal was the last brought into subjection, owing, perhaps, to man's limited and inaccurate knowledge of his nature, and his consequent inability to control him. This fact alone is sufficient evidence of his superiority over all other animals...