Who is Duke Orilus from Parzival and what is their importance?

Duke Orilus is Lady Jeschute's husband. He treats her poorly after Parzival steals her ring because he believes she has betrayed him. Later in the story, Parzival defeats him in a joust. It is after the joust that Orilus learns that his wife did not betray him. As terms of his surrender, Orilus reconciles with his wife and presents his surrender to King Arthur and Lady Cunneware, who is his sister.