In A Feast for Crows Brienne calls Gendry, M'Lord because he looks so much like Renly Baratheon. She is certain, after she learns his name and his story, that he MUST be one of the Baratheon bastards that are rumored to be throughout the kingdom. Renly Baratheon was the youngest son of the Baratheons and the one that Brienne was pledged to as a knight. She was also in love with him.
