Vichitravirya married only her sisters, because Amba told to Bheesma that she is in love with king of Salva and not ready to marry Vichitravirya. Hearing thus from her, Bheesma had a discussion with many learned man and Brahmins and permitted Amba to go to Salva's place. But he rejected her as well in shame of losing the combat against Bhishma at the Swayamvara. Amba then returned to Bhishma and demanded that he marry her. He declined since he had already taken a vow of bachelorhood. Enraged that she was going to be an unmarriageable woman, she swore to kill him, at least in her next life,and went to Guru Parshuram who was the teacher of bhishma. Parshuram called bhishma and asked him to marry amba or have a fight with him. bhishma decided to fight with parshuram and they had a great fight and at the end Bhishma won the battle but amba revenge was not done.she did great prayers and penance and gained wish from lord shiva that she would be the reason for bhishma death in the next birth.