In "A Game of Thrones" (1996), Jaime is introduced as one of the Kingsguard, the royal security detail, and the son of the wealthy and powerful Tywin Lannister, the former Hand of the King. Jaime's twin is Cersei, the Queen of Westeros by virtue of her marriage to King Robert Baratheon. Perhaps the greatest swordsman in the kingdom, Jaime is derisively referred to as "the Kingslayer" because he killed the "Mad King" Aerys Targaryen in the coup that put Robert on the Iron Throne.