Cassana Estermont

Lady Cassana Baratheon, née Estermont, was the younger sister of Eldon and Lomas Estermont. She was married to Lord Steffon Baratheon and gave birth to three sons, Robert, Stannis and Renly. She was killed alongside her husband when their ship was destroyed in a storm, whilst in sight of Storm's End. Her death was witnessed by her two elder sons, Robert and Stannis. Her eldest son, Robert, would go on to lead a rebellion against House Targaryen, ultimately becoming the ruler of the Seven Kingdoms.