Brienne of Tarth, also known as Brienne the Maid was a member of House Tarth and the wielder of the Valyrian Steel blade Oathkeeper. She is frequently associated with the tale of the The Lady and the Lion, although she refused to affirm or deny these assumptions before her death after the Second War of Conquest.
Brienne of Tarth would find herself face to face with Lady Stoneheart and Jaime Lannister, both of whom she had made promises to. Brienne, wielding Oathkeeper would be made to duel Jaime Lannister by the Brotherhood Without Banners, although it is unclear of what exactly the outcome was.
Many suggest that Brienne slew the Kingslayer, while others state that Ser Jaime allowed himself to be felled to spare the maid. Some even suggest that there was no duel, and that both Jaime and Brienne were released unscathed. Whatever the result, Brienne would return to Tarth in the year 305 AC, after some time fighting with the Brotherhood without Banners.
Her sword, Oathkeeper has been passed down to Tarth Lords and Ladies since her passing.