Gereint is a knight who becomes the ruler of Cornwall and who has to learn to balance the demands of love and duty. He is a member of Arthur's court.
His father's name is Erbin, who surrenders the kingdom to a younger man, and Gereint is married to Enid. Gereint is described as having red hair and being well-dressed. He is also a heavy sleeper.
Gereint is a silent man who is irritated both by his wife's inability to hold her tongue and by his suspicions of her infidelity. His marriage to Enid begins as a marriage of convienience enabling him to fight for the honour of one of Gwenwhyfar's handmaidens, but this relationship changes and matures into a balanced and loving marriage, albeit one that faces difficulties.