Bhishma Pitamah has been one of the most prominent characters of Mahabharata, who was the son of Maharaj Shantanu and Goddess Ganga. He was blessed by his father with the boon of Iccha Mrityu. Although he was named Devavrata at birth, he was named Bhishma due to his vow of not marrying throughout his life.

Shantanu broke his promise

Ganga had taken a promise from Shantanu that he would never interfere in any of her work. Bound by this promise, even after Ganga drowned her 7 sons in the river, Shantanu could not say anything. But when Goddess Ganga was about to do the same with the eighth son, Shantanu stopped her and asked the reason for this. To this Maa Ganga replied that I am freeing my sons from a curse given by Vasishtha Rishi. But the eighth son could not be freed from this curse. That child was none other than Bhishma Pitamah.

Why the 8th son could not be freed

According to the legend, those eight sons of Ganga were the 8 Vasu incarnations in their previous birth. Out of which one Vasu named Dyu along with others had stolen the Kamdhenu cow of Sage Vasishta. When the sage came to know about this, he became extremely angry. In anger, Sage Vasishta cursed all of them that they would all be born as humans in the mortal world and would have to face many kinds of sufferings.

When all of them realized their mistake, they apologized to the sage. Sage Vashishtha said that the other seven Vasus will get salvation, but Dyu will have to suffer the consequences of his actions. This is the reason why the eighth son i.e. Bhishma Pitamah could not get freedom from this curse.