Damas is the elder brother of Ontzlake. The two brothers have feuded for over seven years concerning their lands. Damas, the elder but false brother, wishes to keep all the lands for himself but Ontzlake continues to maintain a rich manor. The brothers' forces have fought together with Ontzlake always the victor and Ontzlake has challenged Damas to direct combat. But Damas realizes that he is no match for his brother and has been waylaying knights and imprisoning them in hope of finding a champion to fight his brother. During the seven years, he has captured over twenty knights who have refused him until Morgan le Fay places Arthur in his grasp. Each captured knight is offered freedom if he will fight for Damas. When the maiden goes to Arthur, he seems to recognize her from court but can not place where he has seen her (for she is one of Morgan's women). He agrees to the fight as long as all the other knights are freed and that he is given arms.
   When Damas sees him, not recognizing Arthur but seeing a knight of prowess, he eagerly agrees and sends word to his brother to prepare for the combat.
   But Ontzlake is wounded and unable to fight and accepts Accolon's offer to fight in his stead. The battle between Arthur and Accolon is fierce because Morgan has provided Excalibur to Accolon. During the battle, Damas will not come to an accord with his brother. In the end, Arthur's great skill and courage, and a small enchantment from Nimue to loosen Accolon grip on Excalibur, allow Arthur to regain Excalibur and strike down Accolon. Thus, Damas' cause is achieved but Arthur's true identity is revealed and he rules against Damas. He awards all of the estates to Ontzlake, with Ontzlake to provide for Damas' welfare and to give him a palfrey (a woman's horse) to ride upon. Damas is ordered to restore all of the twenty knights and to never distress any other knight. If any complaint against him reached the court, he would be put to death.