Bhishma Pitamah was one of the most important characters in the Mahabharata. He was the son of king Shantanu and queen Ganga. King Shantanu was again married later to Satyavati. It is believed that to get his father married to Satyavati, Bhishma had vowed to leave the whole throne and remain a celibate throughout his life.
Satyavati bore two sons who were named Chitrangad and Vichitraveerya. Bhishma kidnapped the three daughters - Amaba, Amabika and Ambalika of the Kashi King. He wanted to get them married to Chitrangad and Vichitraveerya. It is believed that while Ambika and Ambalika agreed to marry, Amba did not give her consent. She loved Shalya, the king of Chedi and wanted to get married to him. However, when Shalya denied to marry her, she came back to Bhishma and asked him to marry her. But since Bhishma too had sworn not to marry all his life, he also denied her proposal.
Amba Cursed Bhishma Pitamah
Disappointed and hurt by this, Amba cursed Bhishma that just as her life has proved a waste and has gone all in vain, his life too will similarly prove to be a waste and go in vain one day. She swore that she will take birth as a man and be the reason of his death soon.
Amba Born As Shikhandi
To take the revenge, Amba worshiped Lord Shiva through deep meditation and penance. As a blessing, she was born as the daughter of Panchal King Drupad in her next life. This girl was named Shikhandi. It is believed that when the girl was born, there was a divine prophecy heard in the sky that the girl should be brought up as a boy. Bhishma on the other part of the scene, had grown old till then.
Arjuna Attacked Bhishma Pitamah
Brought up as a boy, Shikhandi also fought in the war of Mahabharata on the sides of the Pandavas. The moment she entered the battle field, Bhishma Pitamah recognized her. While Shikhandi stood before Bhishma Pitamah, Arjuna came and from her back, he targeted Bhishma and laid him down with the arrows. This way, Shikhandi became the reason for Bhishma's death and she took her revenge as she had vowed.
Bhishma Pitamah Did Not Die
However, Bhishma Pitamah still did not die. Lying on the bed of arrows, he was still alive. There is a story behind this as well. He had a boon which he received as a blessing from his father. When he had vowed never to marry, his father gave him the boon of "Ichha Mrityu" or self-declared death. It meant that he will die only when he himself wished to. Therefore, though he lay on the bed of arrows, he would not die until he wanted to.
So, he watched the battle lying on the arrows all the time. As per the rule, the battle used to be stopped after the sunset every day. At this time, all the warriors used to sit around him and listen to his intelligent discourses and lectures.
Droupadi Mocks At Him
One day, while he was surrounded by his kins and warriors, Droupadi happened to come there. Thinking something deep inside her heart, she laughed at him mockingly. Displeased by her, Bhishma Pitamah told her that such behavior was against the standards of the queen of Hastinapur. Well Droupadi, having the last laugh, gave the most intelligent answer. She said that when she was being molested in front of the whole gathering, by the Kouravas, was that behaviour up to the standards of the Kourava Kings? Or was it right for the senior most among them, Bhishma Pitamah, to be silent and not stop the Kouravas when they were doing such a sinful act, was that behaviour up to the standards of Bhishma Pitamah?
Realizing the grave truth in Droupadi's words, Bhishma Pitamah repented for all that had happened and said that since he was living with the Kouravas, he could not oppose them and therefore asked her to forgive him.