Appearance and Personality
Kevan Lannister has fair-skin, golden hair, a close-cropped beard covering his huge jaw, a portly and thick frame and fierce green eyes. He is a dignified, but not entirely handsome man.
Even though many men respected Tywin as the superior brother, a great many people recognise that Kevan is no fool either. Kevan is shrewd, intelligent, efficient and exceptionally competent at the tasks that his brother has set him to the point that he is Tywin's most trusted advisor. All of Tywin's children admire him to some extent, and with good reason: Kevan is capable of being on good speaking terms with each of them, even Tyrion (whom Tywin irreparably hates). At Tyrion's trial, Kevan speaks frequently with him and is almost reasonable with him to compare with everyone else.
Because of Tywin's absolute power in the westerlands, and Westeros as a whole, Kevan has perpetually lived in his shadow, but in his own right he has thrived. He is an important figure of command during the War of the Five Kings, proving himself a competent commander and diplomat. He shares his brother's keen strategic thinking, and resoluteness, even though he may lack the ruthlessness that Tywin grew renowned for. After his brother's death, Kevan proves himself further to be effective, so much that Varys eventually had to kill him to stop him from repairing the damage done by Cersei's arrogance.
Kevan is a loyal man, an affectionate husband and a loving father. Varys considers him to be a good man in service to a bad cause.
Kevan was considered subservient to his older brother, Tywin. In fact, he served as Captain to Tywin for several years. Kevan fought in a battle at King's Landing but was thrown from his horse when the horse became startled by the flaming sword of the priest, Thoros of Myr.
A Clash of Kings
At Tywin's behest, Kevan takes part in the Battle of the Blackwater.
A Storm of Swords
Kevan partakes very little of King's Landings politics, mostly concerning himself with family matters including his sons Lancel and Martyn.
A Feast for Crows
Kevan mourns his brother Tywin. He is soon offered a position as Hand of the King by Cersei. However, he easily sees through the ploy, calling Cersei out for lining the council with those who would be subservient to her and being an ineffective queen. He demands his own terms, one of which is Cersei returning to Casterly Rock as a married lady. Furious, Cersei refuses his offer, and Kevan returns to Casterly Rock with Tywin's body, as a means of giving him a proper resting place.
After Cersei is stripped of her title and imprisoned, he is offered the position of Lord Regent for Tommen.
A Dance With Dragons
Kevan became regent to King Tommen in order to undo the damage that Cersei caused. He was also responsible for making Mace Tyrell hand of the King. He also made two of Tyrell's men members of the small council: Paxter Redwyne became Master of Ships, and Lord Randyll Tarly became the Master of Laws.
He was later lured to Grand Maester Pycelle 's chambers and then shot with a crossbow by the spider, Varys for trying to undo all of the chaos his niece Cersei had caused. He was then stabbed to death by Varys' "little birds".