Character from House of the Dragon by George R.R. Martin
Lord of Casterly Rock and twin brother of Tyland, a proud Green supporter who courted Rhaenyra unsuccessfully and died fighting in the Riverlands — brave enough for the battlefield but not clever enough to survive it.
Jason is the Lannister who got the charm and the castle while his twin Tyland got the brains. He is affable, generous with his wealth, and entirely conventional in his ambitions — he wants glory, a beautiful wife, and the respect his name already commands. He once courted Rhaenyra at a tourney and was rebuffed, which stung his pride enough to push him toward the Greens when the time came. He raised a Lannister host and marched into the Riverlands to fight for Aegon II's cause. He was brave in battle — the Lannisters have never lacked for personal courage — but the Riverlands campaign was a meatgrinder, and Jason fell in the fighting. His death was neither glorious nor ignominious, simply the arithmetic of war catching up to a man who believed his name would protect him from it.
Golden-haired and green-eyed in the classic Lannister mold, handsome in a polished, self-aware way. Wears crimson and gold with the lion of Lannister displayed prominently on everything he owns. Clean-shaven, with an easy smile that suggests he has never had to work very hard for anything. Carries himself with the relaxed confidence of immense inherited wealth.
Also known as: Jason, Lord Lannister, Lord of Casterly Rock