What is the role of the Fairy King in Sir Orfeo?

After Orfeo has a dream in which his wife, Heurodis, is abducted by the fairy king, he takes every precaution to prevent this from happening—but to no avail. The fairy king takes her, and Orfeo becomes so distraught that he wanders aimlessly for years. After glimpsing her in a group of women, he follows her to the fairy kingdom. He charms his way into the castle by playing his harp. The fairy king does not recognize Orfeo, who has let his beard grow long.
So impressed is the king with Orfeo's playing that he offers him whatever he desires. His request is of course for Heurodis, and despite the king's reluctance, his honor requires him to stand by his word. Orfeo takes her back to their own kingdom where they resume their rulership.