Jason Lannister
Lord of Casterly Rock, twin to Tyland ÔÇö golden, gallant, and convinced of it. He once courted the princess with the Rock's splendors and was declined with prejudice.
A soul of House Lannister, born at Casterly Rock, sworn to The Greens ÔÇö the King's Party.
The fuller tale
How it ends for them
On the page. Fell at the crossing of the Red Fork (F&B, ch. 5)
The Lord of Casterly Rock took his gallantry to war and died of it early, cut down at the crossing of the Red Fork by a grizzled squire named Pate ÔÇö knighted for it as Pate of Longleaf, the Lionslayer.
The series has not yet reached this stage of the war; Jason Lannister's fate remains ahead of the current seasons.
Fire & Blood has his gallantry catch up with him early: he falls at the crossing of the Red Fork, cut down by a grizzled squire named Pate who is knighted for the kill and remembered afterward as Pate of Longleaf, the Lionslayer ÔÇö a considerably less distinguished end than Jason's own self-regard would presumably have predicted for him.
Their chapters, book by book
Where the page and the screen part
The show's current seasons have not yet reached Jason Lannister's military campaign or its outcome; Fire & Blood covers his march and its end in considerably more specific detail than the series has had occasion to dramatize.
Their journey
Where the two tellings send them to the same place the road runs whole; where they part, the screen keeps the left and the books the right.