Kaikeyi

In Hindu mythology, Kaikeyi was the third and youngest wife of Dasaratha, King of Ayodhya. She was the step-mother of Rama and mother of Bharata. She was an apt charioteer and had saved the life of Dasaratha during a war. As a sign of his gratitude and love to his wife the king promised her three boons. She used this favour later when Rama was about to be crowned as the prince. She asked the king to have her son Bharata to be crowned as the prince instead and send Rama in a 14-years long exile. The third boon was sought because she realised that Rama was very popular with the people and his presence could have resulted in a hyteric backlash from them.

Dasaratha relents to her demands and the life of Rama in the jungles begins, vividly described in the Hindu epic, Ramayana.