Aśvamedha is one of the most anci-ent, but major, sacrifices mentioned in the Vedic literature. It is mentioned in the Ṛgveda (1.162; 163) and described in the Śatapatha Brāhmaṇa (13.1-5) and the Taittirīya Brāhmaṇa (3.8.9). It derives its name from the fact that an ‘aśva’ or a horse is made the ‘medha’ or animal for immolation. Only emperors and very powerful kings who desired sovereignty could afford to perform it. It belongs to the ‘Ahīna’ group of Soma sacrifices, i.e., Soma sacrifices in which Soma is pressed for more than one day; and, this can be from two to twelve days.
The rite begins on the 8th or 9th day of the bright half of the month of Phālguna, when the horse, which must be all white in colour with dark spots, is bound, bathed and consecrated near the fire. The animal is then let off to wander about at will for a year, guarded by an escort of four hundred armed men, including one hundred princes. The kings or chieftains of the places which the horse enters, should either accept the sovereignty of the sacrificer and pay contributions or tie up the horse and face an armed conflict. In case the challenger wins, the sacrifice will get nullified. Even the death or disease of the horse will result in the same and the sacrificer will have to restart the whole process with a new horse. Meanwhile the sacrificer is expected to perform a number of rites everyday, during the period the horse is away.
After the successful completion of the expedition and the return of the horse, the regular rites of the sacrifice commence. It is a Soma sacrifice of three days’ duration. The horse is immolated on the second day, along with a number of other victims, wild and tame, from the elephant to the bee. Before the carcass of the horse is cut up, the chief queen lies down beside it (by way of fertility spell) while an obscene dialogue between the priests and the other women of the king’s harem is enacted. Before the offering of the omentum, ‘brahmodya’ riddles (theological dialogues where questions and riddles are propounded and answered) are proposed and solved. The concluding bath (avabhṛtha-snāna) takes place on the third day.
The sacrifice involves many subordinate rites and large quantities of gifts are given away to the priests and others.
Though long lists of kings who had performed the Aśvamedha have been given in the Vedic works already referred to, the sacrifice itself seems to have become rare even by the time of these works, since they call it as ‘utsanna’ (‘gone out of vogue’). It appears to be a curious mixture of popular religions, tribal and symbolical elements, inextricably mixed up and a remnant of a hoary past.
During the period of recorded history, Puṣyamitra Śuṅga (2nd cent. B. C.), Samudragupta (4th cent. A. D.) and some Cālukyan kings of South India seem to have performed it. The last one to perform it was Jaya Siṁha II of Jaipur in the 18th century.