There was a king of the Ikshvaku race called Saagar who did not have any children. Along with his two wives Vaidharbhi and Shaibya, Saagar went to Mt Kailas and worshipped Lord Shiva. After many years of austerity, Lord Shiva was pleased and told him that both his queens would get pregnant. To the elder, sixty thousand brave boys would be born who would be great warriors but would die because of the wrath of a rishi. The younger queen would give birth to only one child who would be special, very courageous and who would continue his race.
The king returned to his kingdom and soon after, his younger queen gave birth to a beautiful son named as Asamanja. The elder queen delivered a pumpkin. The king thought of throwing away the pumpkin but was stopped by a divine voice, which guided him to remove the seeds of the pumpkin, mix them with ghee and to plant them in pots. Sagar removed sixty thousand seeds from the pumpkin, and soon after, sixty thousand fully grown brave sons arose from the pots. The king was very happy and decided to perform the Ashwamedha yagna or the horse sacrifice.
The sacrificial horse roamed all over the earth and was protected by his sixty thousand warrior sons. One day the horse neared a waterless ocean, and thereafter vanished from sight. The sons searched for the horse in every possible place but could not find the horse. They went to their father who angrily told them to find it and not come back till they had. So, the sixty thousand warriors decided to dig deep into the waterless ocean. At the bottom of the ocean they found the great rishi Kapila in deep meditation. Standing next to him was their horse. Immediately they seized the horse. The Rishi opened his eyes and saw them taking away the horse. In an instant, he opened his inner eye and reduced all sixty thousand warriors to ashes.
The king had previously banished his son from his younger queen, Asamanja, from the kingdom. Now the distraught King approached the son of Asamanja called Anshuman, and pleaded with him to go to look for his sixty thousand uncles who had gone to find the horse. Anshuman followed the hole in the ocean and reached the spot where the rishi was meditating. All around he saw the burnt bones of his uncles. He paid his respects to the Rishi who was very pleased with him and told him to ask for a boon. Anshuman asked for the sacrificial horse to be given to him. The rishi did so and told him that he would become a great king known far and wide for his tremendous courage, exemplary generosity and forgiveness. Anshuman asked what would happen to the spirits of his sixty thousand uncles. The rishi replied that anshuman’s grandson would be a great king and would please the river Ganga in the heavens who would descend to the earth. When her waters fill the oceans once again his sixty thousand uncles who had died here would be free. Anshuman went back to his grandfather who completed his sacrifice. He then crowned Anshuman as king and retired to the forest.