Kaikeyi was the second queen of King Dasharatha of Ayodhya in the Ramayana. She was responsible for sending Sri Ram to 14-year exile in the forest. She was able to accomplish her evil design through the two boons given to her by king Dasharatha. The story begins with Indra, the king of Devas, fighting the demons.
As per Valmiki Ramayana, once, Indra had to fight with Sambara, the king of demons. Dasharatha sided with Indra in the battle, but got badly injured and was about to die. Kaikayi, who had accompanied him to the battle, drove away his chariot and saved the life of Dasharatha.
The king pleased with her service conferred two boons to her. She had the option to get them fulfilled at any time.
As per Brahma Purana, during the battle between Dasharatha and demons, the axle of the king’s chariot broke and Kaikeyi replaced the axle with her hand to prevent the chariot from collapsing. For this courageous effort, the king conferred two boons to her.
She used the two boons to get her son Bharata become the next king and to send Rama on a 14-year exile.