Jason Lannister son of Gerold Lannister

Jason was the youngest of the four sons Lord Gerold Lannister had with his second wife, Lady Rohanne Webber, who vanished without explanation when he was barely a year old. He grew up at Casterly Rock, forever clashing with Tytos, the soft-willed brother destined to inherit the lordship.

At fourteen he got a serving girl with child, who bore him a bastard daughter, Lynora Hill. A year later he seduced Alys, the unmarried daughter of Lord Stackspear, and left her pregnant too; Tytos — pushed, it was said, by his wife Jeyne Marbrand — forced him to marry her. Alys died giving birth to a son, Damon.

Barely fifteen days after the burial, Tytos and Jeyne married him off again, this time to Marla Prester, a woman twice his age who would give him six more children. The couple settled far from Casterly Rock, at the Bonfires, a move that reportedly eased more than one mind back at the castle. As a boy he had been fierce; as a man he grew proud and quarrelsome, ready to belittle his own brother in private yet quicker still to anger if anyone else dared do the same.

The War of the Ninepenny Kings broke out in 260 AC, and since Tytos had no stomach for soldiering, command of the westerlands host — a thousand knights and ten thousand men-at-arms — fell to Ser Jason, who led it to the Stepstones.

That same year he died at Bloodstone, officially of a bowel fever, though rumor held that Maelys Blackfyre had had him killed. Command of the host then passed to Lord Roger Reyne.