Ser Jaime Lannister, known as the Kingslayer, is a knight from House Lannister. He is the second child and first-born son of Lord Tywin Lannister of Casterly Rock and his wife Lady Joanna, also of House Lannister. He is the twin brother of Queen Cersei Lannister.
Raised at the age of fifteen to the Kingsguard of the Mad King, Aerys II Targaryen, Jaime became the youngest member in the history of the prestigious knightly order. He earned the derogatory nickname "Kingslayer" when he treasonously slew King Aerys near the end of Robert's Rebellion.
Jaime was knighted on the battlefield by ser Arthur Dayne for his valor during the campaign against the Kingswood Brotherhood. Later, he was raised to the Kingsguard of King Aerys Targaryen, making him the youngest knight to receive the honor.
Jaime slew King Aerys Targaryen during the sack of King's Landing, indicating the end of Robert's Rebellion. He remained on King Robert's Kingsguard, and later was raised to Lord Commander by Joffery Baratheon after the dismissal of Barristan Selmy.
Ser Lannister would participate in the War of the Five Kings but would suffer a defeat at the hands of Robb Stark which led to his capture. Jaime would remain captured for the rest of the war, and was executed shortly after the death of his father in The Siege of King's Landing.