King Shantanu married Satyawati and led a happy life. Subsequently Satyawati gave birth to two sons; the eldest was Chitrangadh as the king. After the demise of Shantanu, Bhishma crowned Chitrangadh as the king. But the king died shortly there after. So Bhishma coronated Vichitravirya, the second son, as the king. But since the boy was still young, Bhishma ruled the land on his behalf. There was peace and prosperity everywhere. Several years passed. Vichitravirya was now a young man and was of marriageable age.
The king of Kaashi had three daughters by the names of Amba, Ambika and Ambalika, who were renowned for their beauty. A duel was arranged and the king proclaimed that he would give his daughters in marriage to the winner of this duel. Bhishma heard about this and set forth to Kaashi. He defeated all the other princes and left for Hastinapur along with the three princesses. On the way Shalvaraj challenged him to a war but Bhishma defeated him and reached Hastinapur.
Actually, Bhishma had selected these princesses as brides for Vichitravirya. but Amba wanted to marry Shalvaraj and indicated this to Bhishma. She also requested him to send her to Shalvaraj. On hearing this, Bhishma did not want to force her into an unwilling marriage with Vichitravirya. So he sent her back to Shalvaraj. But Shalvaraj was not prepared to accept her. "You can live with whoever carried you away" he scorned. He had not forgotten his humiliation at the hands of Bhishma. Amba returned to Hastinapur with a heavy heart. Bhishma felt sorry for her. By then Vichitravirya had also decided not to marry Amba. She could not bear the humiliation. So she pleaded with Bhishma to marry her. But how could he? Hadn't he taken a vow not to marry He said 'no' to her.
This infuriated Amba. She held Bhishma totally responsible for her plight. Hatred and revenge filled her thoughts. She sought the help of other kings to wage a war against Bhishma but none supported her. Her anger against Bhishma grew stronger. In desperation, She observed a very strict penance, praying to Lord Shiva. Her sole purpose was to kill Bhishma out of her own hands.
Pleased with Amba's penance, Shiva appeared before her. But the boon she wanted was against the divine spirit. "Bhishma has the blessings of all the gods and goddesses said Shiva", Hence, nobody can kill him. But all humans on this earth are bound to die sooner or later. You can kill Bhishma, But not now. You can do so in your next birth upon this earth. You will be born as daughter to Drupad, The king of Panchaal. Your wish will then be fulfilled."
Amba had only one aim in life to kill Bhishma. She was prepared to wait until even her next birth. She therefore headed straight to Dhrupad's palace and jumped into the sacrificial fire "Yagna" being conducted there. Her body was reduced to ashes.Amba was born as Dhrupad's daughter and from the childhood she learned all the lessons of war and fights. She prepared herself as man worrier so that whenever times come she would be able to fight with Bhishma. She was called "Shikhandi" among all worriers and respected as "Maharathi"(the first degree worrier), a worrier who can command a full fledge army. She waited find the opportunity to seek vengeance on Bhishma.