King Santanu was walking along the banks of the river Ganga, admiring its vast expanse and tranquil surface. Suddenly there appeared on the waters a beautiful damsel, dressed in white, walking towards him gracefully. Captivated by her sight, Santanu wanted to know more about her. He beckoned to her and asked her who she was. The maiden introduced herself as Ganga. She seemed to be equally attracted by the king. When Santanu proposed marriage to her, she immediately consented. But she was willing to marry Santanu only on a condition. Once married, he would, at no time, restrain her from doing what she pleased, nor ask her to explain any of her actions.
Santanu took Ganga to his palace where he celebrated his marriage with her. They were soon blessed with a son. But as soon as the baby was born, Ganga carried him to the river and threw him into the water. Santanu who was watching this strange act was helpless to intervene, remembering his promise not to interfere with anything Ganga did.
When the next son was born, Ganga repeated the same act of throwing the baby into the river. This behaviour of Ganga went on till seven sons were born and all the seven were killed. When the eighth son was born, Ganga, as usual, picked up the baby and started walking towards the river.
Santanu had come to the end of his patience. His anger and frustration at seeing his sons thrown into the river got the better of him and he confronted Ganga. He bade her to stop killing his children and demanded an explanation from her for her action.
Ganga told Santanu that since the king had broken the contract made at the time of their marriage, she was leaving him. She would however not kill the eighth child. Ganga then related to Santanu the reason for all her actions. Ganga said :
There is a group of eight demigods in the ether world known as the Vasus, They are always found together. Once, when they were roaming about on earth with their wives, they came to the forest where the sage Vasishta had his hermitage. In the pasture nearby they saw the divine cow, Nandini, the proud possession of the sage. The cow was grazing peacefully. She had a glorious appearance, and her milk, which she yielded in abundance, was known to have a rejuvenating power. The wife of the Vasu Dyau desired to obtain the cow so that she can present it to her dear friend, Jitavati, daughter of the sage Usinara.
Dyau wanted to satisfy his wife’s desire. He found that the sage had left the hermitage and gone to the river. The cow was unguarded and Dyau had no difficulty in capturing her.
When the sage returned to the hermitage, he found the cow missing. Through his vision he learnt that the Vasus had abducted her in his absence. An angry Vasishta cursed the Vasus, “Because you stole the cow Nandini, you should all be born as humans on earth.”
Realising their mistake, the Vasus rushed to the sage and fell at his feet, begging forgiveness. They prayed for the withdrawal of the curse. It is in the nature of a curse that once it is given, it cannot be withdrawn. It can however be modified or redemption can be offered.
Vasishta felt pacified and he modified the curse. He said that the Vasus cannot escape from being born on earth. But they could return to heaven immediately after their birth. That is, all of them except Dyau who actually stole the cow. He will remain on earth for a longer period. While on earth, he would be devoted to his father. Due to his strength, virtue and knowledge, his fame would spread far and wide. But female companionship or progeny, he will have none.
“The Vasus then approached me,” Ganga continued. “After explaining their predicament, they sought my help. They desired to be born to me on earth. I agreed to help them in their deliverance.”
The seven children which were born to me were seven of the Vasus. I killed them immediately so that they could return to heaven. The eighth one, Dyau, who is born as your son now, will remain alive. He will live a noble life on earth until he finally gets his release.”
After relating the story of the Vasus to Santanu, Ganga took the child with her, promising to return him to the king after nursing him through his childhood. She gave the child, who was named Devavrata, the best of education in all disciplines, from Vedas to warfare, under preceptors as distinguished as the sages Vasishta and Parasurama. After some years, Ganga returned Devavrata, now a youth, to Santanu as promised. There was none in the three worlds to equal the handsome young prince in bravery, wisdom and dedication to truth. Santanu installed Devavrata as his heir apparent.