If this isn't a character from the books, why did we assume he's part of the specific cadet branch "House Lannister of Lannisport" (which is in the books) and not just a distant cousin of the main "House Lannister"? He did go back home to Lannisport, but that's just the Lannister's main city; even Joanna Lannister was from Lannisport but not part of a cadet branch. Did they ever say he was in the cadet branch?--The Dragon Demands 19:04, May 5, 2012 (UTC)

Actually, Joanna was born at Casterly Rock according to AWOIAF.--Gonzalo84 23:26, May 5, 2012 (UTC)
It cites no evidence; it may be an assumption. --The Dragon Demands 00:00, May 6, 2012 (UTC)
Well... leaving Joanna aside:
        • Tywin cites the "name" before actual family (meaning they are not closely related)
        • He's from Lannisport.
        • Lannisport is in TV!GoT stated to be ruled by a cadet branch of House Lannister.

Yes, its part speculation, but for these cases we reconcile show evidence with books canon --Gonzalo84 08:40, May 6, 2012 (UTC)

I'll have to check on this for Joanna; I still vaguely remember from the books that she was part of the cadet branch in Lannisport....--The Dragon Demands 14:18, May 6, 2012 (UTC)