The King's Sadness
King Shantanu fell in love with Satyavati, a fisherman's daughter of extraordinary beauty. He wanted to marry her. Her father agreed — on one condition: Satyavati's son must inherit the throne, not Shantanu's current heir, Devavrata.
Shantanu refused. He went home and fell into a profound sadness, unable to eat or sleep.
Devavrata Investigates
His son Devavrata noticed the king's grief and sought out the reason. When the fisherman's condition was explained, Devavrata went to the fisherman himself.
He gave up his claim to the throne. Done.
The fisherman was not satisfied. What about Devavrata's children? They might contest Satyavati's sons.
Devavrata made his famous vow: "I will never marry. I will never father children. I will never take the throne."
The Name
The heavens trembled at the severity of this vow. The gods rained flowers.
Shantanu, overwhelmed, gave his son a boon: Devavrata could choose the moment of his own death. He would die only when he wished to.
The court named him Bhishma — he of the terrible vow. He kept it for the rest of his long life, through every loss and every war, through the fall of the dynasty he had sacrificed himself to protect.