In the Mahabharata, Bhisma is the uncle of Pandu and Dhritarashtra. He is the son of the River Ganges and King Santanu, and is an incarnation of one of the immortal Vasus. <\p>
King Santanu later had a son, Vicitravirya, by his second wife Satyavati. Bhishma abdicates his right to the throne in favor of Vicitravirya. He also swears that he will never have children - since they might claim a right to the throne. For this selfless and filial act, he is granted the ability not to die until he wills his own death. <\p>
During the battle of Kurukshetra - the main battle of the Mahabharata - Bhishma fights on the side of the Kurus, Dhritarashtra's sons. He is greatly respected by the Pandus, his great-nephews on the other side of the battle. <\p>
In battle, he wears white robes and armor. His flag has a fan palm and five silver star-flowers on a blue background.