Brienne: Lady Sansa, before your mother's death I was her sworn sword. I gave my word I would find you and protect you. I will shield your back and keep your counsel... and give my life for yours if need be. I swear it by the old Gods and the new.
Littlefinger: Please, Lady Brienne no need for such formality. You were Catelyn Stark's sworn sword?
Brienne: I was.
Littlefinger: Strange I knew Catelyn from the time we were children, she never mentioned you.
Brienne: It was after Renly's murder.
Littlefinger: Ah yes.