Doran Martell from A Feast for Crows is the prince of Dorne and the guardian for Myrcella, but in name only. He is so ill that he's little more than an invalid. He has terrible bouts of gout which cause him to be a ruler in name only. When he learns that his neices and daughter play to raise Myrcella up as the queen he stems off war by having their plot foiled, imprisoning the girls, and killing most of the perpetrators. Myrcella is left disfigured because of this.
