The Ashvamedha was a horse sacrifice ritual followed by the Śrauta tradition of Vedic religion. It was used by ancient Indian kings to prove their imperial sovereignty: a horse accompanied by the king's warriors would be released to wander for a year. In the territory traversed by the horse, any rival could dispute the king's authority by challenging the warriors accompanying it. After one year, if no enemy had managed to kill or capture the horse, the animal would be guided back to the king's capital. It would be then sacrificed, and the king would be declared as an undisputed sovereign.
