"Kingslayer" redirects here. For the act of killing a king, see: Regicide Ser Jaime Lannister was the elder son of Lord Tywin Lannister, younger twin brother of Queen Cersei, and older brother of Tyrion. He was involved in an incestuous relationship with Cersei, and unknown to most, he was the biological father of her three bastard children, Joffrey, Myrcella, and Tommen, as well as her unborn child. During Robert's Rebellion, Jaime killed Aerys Targaryen, earning the derogatory nickname...