Sack of King's Landing
The Sack of King’s Landing occurred one year into Robert's Rebellion. Lord Tywin Lannister, who had remained neutral until the Battle of the Trident, marched to the gates of King’s Landing, claiming loyalty to Aerys II and asking to be let in. Aerys favored the advice of Grand Maester Pycelle over that of his spymaster Varys and opened the gates of the city. The Lannister forces then began to sack the city in Robert's name. Aerys ordered his most recent Hand, the pyromancer Rossart, to ignite the wildfire caches throughout the city, saying, "Let him [Robert] be king over charred bones and cooked meat. Let him be the king of ashes."
Aerys then ordered Jaime Lannister, one of his Kingsguard and Tywin's own son, to kill his father. Instead, Jaime slew Lord Rossart and then murdered Aerys himself on the Iron Throne. Tywin sent his knights Ser Gregor Clegane and Ser Amory Lorch to deal with the rest of the royal family, securing the throne for Robert and proving that House Lannister had forsaken the Targaryens forever. Gregor killed the baby crown prince Aegon Targaryen while his mother watched, and then proceeded to rape and murder Princess Elia herself. Amory dragged princess Rhaenys from under her father's bed and killed her. When Eddard Stark arrived shortly thereafter, he found Jaime seated on the Iron Throne and Aerys's corpse slumped below it. Tywin Lannister presented the bodies of Elia, Aegon and Rhaenys as tokens of his fealty. The resulting argument led to Eddard Stark riding out alone to finish the war in the south.