Cersei's infidelity and confronts her, giving her the opportunity to flee into exile and thus spare her children certain execution. Cersei had already arranged Robert's death in a hunting "accident"; when he dies, Cersei seizes control as regent and has Eddard arrested for treason. Cersei intends for Ned to publicly confess and join the Night's Watch as punishment, but instead Joffrey orders him executed. A Clash of Kings Frustrated with Cersei's many political blunders as well as her failure to control Joffrey, Tywin appoints Tyrion Hand of the King, with explicit instructions to control Cersei and Joffrey. Once at the capital, Tyrion enters into a bitter power struggle with Cersei, subverting her authority and removing her supporters from positions of power. In Jaime's absence, Cersei takes their cousin Lancel Lannister as her lover, an affair that Tyrion discovers. When Stannis Baratheon sails on King's Landing, Cersei and Joffrey stay enclosed in the Red Keep, leaving Tyrion to mastermind the defense of the city. Ultimately, Tywin and the Tyrell armies arrive in time to force Stannis to retreat and save the city. A Storm of Swords After formally assuming his position as Hand of the King, Tywin makes it clear to Cersei that she is no longer welcome at the small council meetings, de facto stripping her of political authority. Furthermore, Tywin intends to wed Cersei to Willas Tyrell in order to form an alliance with House Tyrell. This state of affairs is shaken when Joffrey is poisoned at his wedding feast. Maddened with grief at the loss of her eldest child, Cersei lashes out against Tyrion, accusing him of poisoning the king out of revenge. Cersei manipulates Tyrion's trial to ensure a guilty verdict, by bribing and intimidating witnesses. When Tyrion demands a trial by combat, Cersei selects the imposing Gregor Clegane, "The Mountain," as the Crown's champion. The Mountain prevails, killing Tyrion's champion Oberyn Martell. Tywin then pronounces Tyrion guilty and sentences him to death, but Tyrion escapes prison and kills Tywin. Cersei is once again in complete control of the capital. A Feast for Crows With the deaths of her father and elder son, Cersei's youngest child, the 8-year-old Tommen Baratheon, is crowned king, and Cersei rules the Seven Kingdoms as Queen Regent. Cersei's rule descends into a series of political and economic blunders due to her short temper, egotism, and paranoia, greatly damaging her relationship with Jaime