As you read through the story, one of the comforting sections in its confusing narrative is Peredur’s meeting with Angharad. She becomes and remains his love interest throughout the rest of the story. Angharad is a great plot device and comes into play just in time. Peredur originally leaves his mother to join Arthur as a knight. After his mishap with Cei and the Black Knight, though, that motive fades. Having the hero meet the woman of his dreams gives Peredur a reason to keep pursuing quests, but also a tactile reward for his accomplishments.
But that’s just the literary reason why she appears. The cultural reason is a familiar one to those who have studied Welsh stories, her presence represents the sovereignty aspect of the tale. Angharad, even though she possesses a real Welsh name and behaves like a woman, is the symbol for a kingdom. Peredur’s marriage to her will mean that he has ascended to a throne.