Amba was the eldest daughter of King of Kashi. He was kidnapped by Bhishma to get her married to his step brother Vichitraveerya but Amba told Bhishma that she was in love with King Shalya. Bhishma allowed her to go to Shalya but king Shalya refused to marry her. Everyone tried to convince Bhishma to Marry Amba but he refused due to his oath about not to marry ever. Amba then wants to kill Bhishma and take revenge. How it happens this story tells everything about it. 

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