Belliance le Orgulus
Sir Lamorak saved Sir Frol of the Out Isles from four knights who were fighting Frol all at once. Shortly thereafter Lamorak and Frol had a tiff and separated. Three or four days later Lamorak came along again and saw Frol give Gawaine a fall when Gawaine tricked to take Frol's lady. Lamorak jousted with Frol to avenge Gawaine, and by mischance smote Frol fatally. Frol's brother, Sir Belliance le Orgulus, came to avenge Frol. Learning Lamorak's identity, Belliance said,
Ah, thou art the man in the world that I most hate, for I slew my sons for thy sake, where I saved my life, and now thou hast slain my brother Sir Frol.
Lamorak tried to beg Belliance's pardon, but Belliance insisted on fighting. Lamorak fought him down but refused to kill him, thereby winning his friendship so that they swore never again to fight each other.
Belliance is probably the "Sir Bellangere le Orgulus, that the good knight Sir Lamorak won in plain battle", who is listed as a knight of the Round Table. He should not be confused with Bellengerus le Beuse, who is also sometimes called "Bellangere".