HORSES have played an essential role in the life, and therefore in the religion, of all the peoples who have had direct contact with them, particularly the Indo-Europeans, the ancient Mesopotamians and Egyptians, the Arabs, the Chinese, and the North American Indians. It is fair to say that horses have always captured the mythic imagination through their ability to symbolize a number of related phenomena: power, wealth, divinity, sexuality, flying, and the tension between taming and freedom.

Among the earliest evidence of the importance of the horse to human culture are the magnificent wall paintings in the caves of Lascaux, in southern France, dating from around 30,000 BCE. There the grouping of horses with other wild animals such as stags and bison suggests that they were probably animals that were hunted rather than harnessed or ridden. Even so, it has been proposed that certain structures depicted on the walls...