First born of Lord Tytos Lannister and Jeyne Marbrand, sent in his boyhood to King's Landing as cupbearer to King Aegon V Targaryen, where he made fast friends with the young Prince Aerys and Steffon Baratheon, the heir to Storm's End. He won his spurs in the War of the Ninepenny Kings on the Stepstones in 260 AC and was granted the honor of dubbing Prince Aerys a knight in the field. He returned to a westerlands grown brazen with the laxity of his father, whose bannermen mocked the Lord of Casterly Rock and forgave their own debts to him. When Houses Reyne of Castamere and Tarbeck of Tarbeck Hall renounced their fealty in 261 AC, Tywin raised the host of the Rock without his father's leave, threw Tarbeck Hall down upon Lady Ellyn's head, and ended the Reyne revolt by turning a stream into the subterranean galleries of Castamere and drowning the house entire. The two ruined holds were left to silence the laughter of the west, and a song called The Rains of Castamere was made to carry the lesson into the harps of any house that thought of forgetting it.
When Aerys II ascended in 262 AC he made his old friend Hand of the King, the youngest man yet to wear the chain; the realm prospered in coin and trade for ten years upon Tywin's accounting, and he wed his cousin Joanna Lannister in 263 AC, who gave him the twins Cersei and Jaime in 266 AC. But the king lusted after Joanna at her bedding and the queen sent her from court, and as the years drew on Aerys grew jealous of his Hand's competence and began to overrule his judgments for spite. In 273 AC Joanna died bringing Tyrion into the world; Tywin took no other wife and the dwarf-son he blamed for her death he ever after despised. After Duskendale in 277 AC Aerys was convinced that his Hand had meant for him to die there so Cersei might wed Rhaegar, and from that day Tywin was met only in the Kingsguard's company. When in 281 AC the king named Jaime to the white cloaks to rob Tywin of his prized heir, the Hand pleaded ill and went home to Casterly Rock with his chain set aside.
He sat the Rebellion out behind his closed gates while bannermen on both sides begged his aid, and only when Robert had killed Rhaegar at the ruby ford of the Trident did the Lord of Casterly Rock ride for King's Landing — admitted within the walls by Aerys at Grand Maester Pycelle's urging, and falling upon the city in sack the moment his westermen were inside. His son Jaime put a sword through the mad king at the foot of the Iron Throne, while Ser Gregor Clegane and Ser Amory Lorch, knights of his own household, slew Princess Elia of Dorne in her bed and her two small children with her; their bodies were wrapped in crimson Lannister cloaks to hide the blood and laid at King Robert's feet as a token of fealty. Dorne never forgave it. Cersei was wed to the new king to seal the bargain, Ser Ilyn Payne given the King's Justice as a wedding gift, and Tywin retired to Casterly Rock to keep the Warden's seat and to lend the crown the gold its drunken king could not stop spending. There he made a sharp lesson of his dwarf son's first marriage by giving the common girl Tysha to his garrison for a silver each, and there he sat as Lord of the Rock through the long peace until a raven from his daughter brought word that Lord Eddard Stark was Hand and the time of his retirement was at its end.