Jason Lannister
Not to be confused with Jason Lannister (son of Gerold).
Jason Lannister was Lord of Casterly Rock, Shield of Lannisport and Warden of the West during the reign of Viserys I Targaryen. When the Dance of the Dragons broke out, he threw his house behind Aegon II and led its forces toward the Riverlands.
The elder twin of Ser Tyland Lannister, he married Lady Johanna Westerling and had several children with her, including his heir, Loreon.
Chapter 1
The feast at Casterly Rock
112 AC
In 112 AC Rhaenyra Targaryen traveled to the Westerlands, and Casterly Rock welcomed her with a feast where Jason and his twin brother Tyland openly vied for her attention.
Not long after, Jason married Lady Johanna Westerling, daughter of the Lord of the Crag. They had five daughters — among them Cerelle and Tyshara — and a single son, Loreon, his heir.
He was described as a tall, fair-haired, good-looking man.
Chapter 2
The advance on the Red Fork
130 AC
When the Dance of the Dragons began, Lord Jason declared for Aegon II and raised a host of a thousand knights, with seven times that number in soldiers and archers, to strike the Riverlands from the east.
The plan was to link up with Prince Aemond, who was advancing from the west with troops brought from King's Landing, so the two could meet at Harrenhal, then held by Daemon Targaryen.
Ordered to cross the Red Fork, Jason found the crossing held by the men of Lord Petyr Piper and Lord Tristan Vance. On the third attempt he was mortally wounded by a squire, who was knighted for the feat. Lord Humfrey Lefford then took command of his men, but the march that followed ended in disaster.
Chapter 3
The sack of Lannisport
130 AC
While Jason fought in the Riverlands, the Red Kraken landed with his ironborn at Lannisport, sacked the town and carried off hundreds of women and girls to make them salt wives. Among those taken were Jason's favorite mistress and the daughters he had had with her.
His son Loreon inherited Casterly Rock, but since he was only four years old, it was his mother, Lady Johanna, who ruled in his name and had to deal with the raiders and with the aftermath of the civil war.