Brightroar was the Valyrian steel blade of House Lannister. It was lost when Tommen II Lannister, King of the Rock, took it on his expedition to the ruins of Valyria and disappeared. The lack of a Valyrian steel sword for House Lannister drove Tywin Lannister to have Ice, the Valyrian steel greatsword of House Stark, reforged into two blades.