Final answer:
Arthur displays the quality of bravery and honor.
Step-by-step explanation:
Arthur displays the quality of bravery and honor that makes him a chivalrous character. In the given text, it is mentioned that Arthur is hardy, rich, wise, merciful, just, true to his word, benign, honorable, and ambitious in warfare. These characteristics demonstrate his bravery in battle and his commitment to upholding the code of chivalry.