Addam Marbrand

A Lannister bannerman is an unnamed minor character in Game of Thrones. He is played by guest star B.J. Hogg and only appears in the tenth episode of the first season.

Season 1
He is present for a strategy meeting with Tywin following the defeat in the Battle of the Whispering Wood. He wears a red cloak over his armor. Also present are Tyrion Lannister, Kevan Lannister, two other bannermen, Tywin's servant and several Lannister officers. He asks about Stannis and Renly Baratheon. He dismisses the idea of forming a truce citing a desire to appear strong. Tywin dismisses his bannermen and then announces plans to relocate to Harrenhal.

In the books
In the Song of Ice and Fire novels, Ser Addam Marbrand is the most aggressive of the bannermen at the meeting and decries the idea of a truce. However, Marbrand is the same age as Ser Jaime Lannister and has long red hair and wears a smoke grey cape.