After 16 years, a youth was found stopping the water flow of Gangaa with a wall of arrows. People complained about this to Shantanu. Shantanu himself went to see that. He found a young man doing this, then he got ready to have a fight with him, the then Gangaa came, introduced him as his son and handed over him to Shantanu. Shantanu brought him home. His Guru were Parashuraam Jee and Brihaspati Jee like teachers. Later he was declared as the Crown Prince of Hastinaapur. After declaring him as Crown Prince Raajaa Shantanu became free of worries.

One day, he noticed that his father was not well for some time. He asked him about his worry, but didn't find a proper answer. He consulted his elders and ministers and came to know that he was in love with Daash Raaj's daughter Satyavatee and Satyavatee's father was not ready to marry her to his father because his astrologer had said that Satyavatee's child would rule the kingdom, and since Shantanu had already declared Devavrat as the Crown Prince how this prediction would be true. 

At this Devavrat vowed that he will never ask for the kingdom and thus only Satyavatee's children will rule the kingdom. At this Daash Raaj said - "You are a great Prince, but what would happen if your children will claim the kingdom later and fight with Satyavatee's children?" Then he again vowed that not only he will ask kingdom, but he wouldn't marry lifelong so that he would not have any children who will ask kingdom from Satyavatee's children. At that time Devtaa showered flowers and Aakaashvaanee said - "Only you can take such a Bheeshm vow so from today you will be known as "Bheeshm" in Trilok. Neither anybody has taken such a vow before, nor anybody will take such a vow in future." Since then nobody knows his real name and he is popularly known as Bheeshm.

And since then, because of taking such a great and difficult vow, he was called Bheeshm (Bheeshm means difficult) and got popularly known as Bheeshm Pitaamah. Seeing his dedication to himself his father Shantanu also gave him the Var of Ichchhaa Mrityu. (Bheeshm would die only whenever he wanted to die, and Mrityu will not come to him without his wish.)

He was indeed a great warrior, he even satisfied his Guru Parashuraam Jee in a fight. He was a knowledgeable person and a great devotee of Bhagvaan. He was the first army chief of Kaurav army and remained their chief up to 10 days. Then he laid on the bed of arrows for a few days more - until the Sun came Uttaraayan and the Hastinaapur kingdom got secured from all sides. In the end Yudhishthir came for his guidance about politics and political matters and other matters of life. He left his mortal body looking at Shree Krishn

Shantanu and Satyavatee had two sons in the course of time: Chitraangad and Vichitraveerya. Both grew up as a handsome brave mighty young men. When Chitraangad grew up, Bheeshm appointed him as the king. He won many Devtaa, people, countries. Once he had a fight with a Gandharv named also Chitraangad on just a trivial matter "why do you have my name?" The fight continued for three years. At last the king Chitraangad was killed by Gandharv Chitraangad. Then Bheeshm appointed Vichitraveerya as the king of Hastinaapur.

Now Satyavatee became worried about the heir of Hastinaapur so she asked Bheeshm to marry Vichitraveerya. At that time Kaashee's king Kaashee Raaj had three daughters - Ambaa, Ambikaa, and Ambaalikaa. They were of marriageable age so he was organizing their Swayamvar. When Bheeshm came to know about this, he alone went there. Everybody was surprised to see him there because he had already vowed to remain unmarried. But He declared - "I am here on behalf of the king of Hastinaapur. For generations Kaashee's princesses have been married in Hastinaapur royal family, so by organizing this Swayamvar Kaashee Raaj has insulted us. I am taking these three princesses to Hastinaapur for my younger brother, if anybody wants to stop me, he may." But then who had the courage to do so.  

So he took the three princesses of Kaashee to marry his step brother Vichitraveerya, Satyavatee's son. Shaalv Kumaar wanted to marry Ambaa so he followed them and had a brief fight with Bheeshm, but as it is clear that he was not a match to Bheeshm, so he had to come back. He was given his life back to him.

When Bheeshm had brought them to Hastinaapur then Ambaa declared to Satyavatee that she loved Shaalv Kumaar only and she wanted to marry him only. Satyavatee asked Bheeshm that why should he bring her if she loved someone else? Bheeshm said - "She had not told me there, otherwise why should I have brought her here?" On asking "why didn't you tell this there only?" Ambaa said - "I got scared of Bheeshm."

Well, Satyavatee asked Bheeshm to send her back to Shaalv with great respect. But Shaalv Kumaar did not accept her as he felt insulted. She came back to Hastinaapur and asked Vichitraveerya for justice. She blamed Bheeshm for all this and as a punishment she asked that he should marry her. But Bheeshm could not have married her at any cost because first thing he did not bring them for himself, second he had already vowed to remain unmarried throughout his life. At this Ambaa in a great fury, vowed in the royal court that she would take the revenge of her insult from Bheeshm even though she has to take any number of births and she will be the cause of his death.

So at one time she was born as Shikhandee as Raajaa Drupad's daughter and became the cause of Bheeshm's death.

Bheshm was the first Commander-in-Chief of Kaurav army. He stayed there in this position for 10 days. Till he was the Commander, he did not allow Karn to fight from his side. On the 1st Day of war he killed Shwet, the elder son of Raajaa Viraat.

On the 9th day Bheeshm declared that the next day either he will kill one Paandav or he will die himself. This was the sign to Yudhishthir to ask Bheeshm about how he will die, because it was clear that he could not have killed any Paandav. 

So on Krishn's advice Paandav went to him for his blessings to win this war which he gave them readily. But how could they win the war till Bheeshm was the army chief of Kaurav army. Then Bheeshm told them that he would not use any weapon on any woman.  Yudhishthir said - "But where we will get a woman in the battlefield?" Bheeshm said - "Go and ask Krishn, He will tell you."

Then Krishn told the whole story of Bheeshm and Ambaa (now born as Shikhandee to take revenge). He went to Shukhandee and said to him - "Now your time has come, for which you had been waiting for several lives. Tomorrow you will fight with Bheeshm." So next day Shikhandee appeared in the battlefield and started shooting arrows at Bheeshm. Bheeshm didn't counterattack him as he considered him as a woman. But still Bheeshm did not die by Shikhandee's attacks, so Krishn asked him to stand on Arjun's chariot in front of Arjun, and then Arjun to shoot arrows from behind him. 

Bheeshm still did not encounter Arjun's arrows as he was shooting from behind Shikhandee. So at one time he was severely wounded and fell down. He had so many arrows on his body that when he fell down, his body didn't touch the ground, he was lying on arrows only. He was removed from the battlefield and he lay down on the bed of arrows until the war came to an end and when he was assured that Hastinaapur was in good hands (Paandav's hands). Besides the Sun at that time was in Southern Hemisphere (Dakshinaayan - see Uttaraayan for its explanation), he did not want to die then, so he waited till it came in Northern Hemisphere (Uttaraayan).  When it was in Northern hemisphere then he left his mortal body. Yudhishthir and his brothers along with Shree Krishn came to learn many things from him about Dahrm, Karm, Upaasanaa, principles of life,  when they had won the war. 

When Bheeshm was explaining Dharm to Dharm Raaj's son, Draupadee broke in laughter. Bheeshm said - "You cannot laugh without reason, tell me the reason of your laughter." Draupadee said - "Pitaamah, When I was being bared in the court, I asked you whether it was justified for Yudhishthir to lose me after he had lost himself in the game? You said that "My mind is not able to decide on this matter. Whatever Yudhishthir says would be right. And today you are preaching him Dharm?" Bheeshm said - "Putree, At that time my intellect was polluted in the company of Kaurav, now since my whole body is pierced by arrows and all polluted blood has come out of the body, I can see what is Dharm?"

He died on the 8th day of Maagh Shukl Paksh.

When Bheeshm heard that Krishn would not take any weapon in His hand in the war, he smiled and said - "Vansheedhar, If I did not force you to take a weapon in your hand, then you tell me." And he did force Krishn to take His Chakra (some say he ran towards Bheeshm carrying the wheel of the chariot) to kill him. Then Arjun pacified Him not to do so.