Brienne of Tarth is a major character in the fourth and fifth seasons. She initially appeared as a recurring character in the second and third seasons. She is played by Gwendoline Christie and debuts in "What is Dead May Never Die." She is a warrior of House Tarth, vassals to House Baratheon. After winning a tournament melee, she is made a member of King Renly Baratheon's new Kingsguard, shortly before his assassination. She becomes the sworn sword of Catelyn Stark and vows to avenge Renly's death. She is charged by Catelyn Stark to return Jaime Lannister to King's Landing, in an attempt to exchange him for her two daughters she believes are held hostage there.