Oathkeeper (sword)

Oathkeeper is the first of the Valyrian steel longswords made from Ice, the greatsword of House Stark, under orders of Lord Tywin Lannister. Lord Tywin made a gift of it the Ser Jaime Lannister, who in turn gave it to Brienne of Tarth for his quest to find and protect Sansa Stark. As a symbol of her promise, Brienne named the sword.