The medieval lay, "Sir Orfeo" is a curious blend of different traditions, cultures and ideas. It is ultimately the story of the clash between magical, pre-Christian spirits and a flawed contemporary (for the time) king. This story drew on and blended several distinct sources for inspiration.

The most obvious source for this work is the classical Greek myth of Orpheus and Eurydice. Many of the names in the work seem to come almost directly from the myth, such Sir Orfeo and his wife Heurodis and the central plot action is remarkably similar: That of a minstrel traveling to another world in order to retrieve his wife from that world's powerful king.

"Sir Orfeo" isn't simply a retelling of the myth of Orpheus in the Underworld, though. there are many surprising differences between "Orfeo" and "Orpheus", and between "Orfeo" and other medieval romances.

The story of Sir Orfeo was greatly influenced by the Celtic mythology. When Heurodis is taken by Celtic fairies and Sir Orfeo travels to the Celtic "Otherworld" to retrieve her. Orfeo is a Celtic minstrel-king in post-Christian times. There are also many other minor touches that are totally in-line with Celtic mythology, such as Heurodis' abduction from beneath a tree, a common practice for fairies.

The Otherworld as presented in Sir Orfeo is a very curious place, but not entirely unfamiliar to Orfeo. There are a great many parallels between Sir Orfeo's world and that of the Fairies. First, when the fairy king comes to Heurodis, he comes to her with "And wele ten hundred knightes with him, Ich y-armed, stout and grim" (183-184) Orfeo is able to muster up that many knights for the defense of his wife: "Wele atourned, ten hundred knightes, Ich y-armed to his rightes" (291-292). Heurodis describes the Fairy Kingdom thus: "And schewed me castels and tours, Rivers, forestes, frith with flours" (159-160), which seems to mimic Sir Orfeo's own kingdom, when the author describes what Orfeo was leaving behind: "He that hadde had castels and tours, River, forest, frith with flours" (245-246).

When Orfeo enters the Fairy Kingdom, he observes a fairy hunting party, with hounds and falcons, but it is an odd hunt, because "Ac no best thai no nome" (287). It seems that much of the Fairy Kingdom is based on mimicking the human world, without truly understanding the purpose. Why else would they go hunting without taking any game? When Sir Orfeo arrives at the castle of the Fairy King, he is able to gain entry as a wandering minstrel. Minstrels were quite common in Sir Orfeo's kingdom, but Orfeo is the first minstrel to visit the Fairy King. The Fairy King is so overjoyed to have a minstrel that he promises Orfeo anything that he wants, because he doesn't know how to reward a minstrel. Orfeo needs only to remind the Fairy King that "gentil king, Yete were it a wele fouler thing To here a lesing of thi mouthe! So, sir, as ye seyd nouthe, What ich wold aski, have y schold, And nedes thou most thi word hold." (464-469). This is because the Fairy Court observes the rules of the ideal medieval society, even if it doesn't understand them.

Both Orfeo and the Classical Orpheus retrieve their wives from the other world by playing their harps for the king. In this way, the action is similar, but the means are slightly different. While, Orpheus moved the King and Queen of the Underworld with his song, Orfeo's song doesn't seem to affect the Fairy King at all. This change may have been made because the Fairy King is little more than an unfeeling mimic, who apes human behavior without any true emotion.

It is also interesting to note that Sir Orfeo holds the Fairy King to his rash promise, on the grounds that a true king can't lie. This is a little bit hypocritical, as Orfeo at that moment is participating in a lie, claiming to be a lowborn minstrel, rather than a king. This may be a difficulty generated by the collision of traditional Celtic stories of humans outsmarting Fairies and the concept of chivalry, which was seen as part of Christianity. Alternatively, it could've been a statement about how the real-life king can't live up to the chivalric ideal which the Fairy King is mimicking, no matter how good his intentions are.

In "Sir Orfeo" we are shown two distinct, yet very similar, worlds. The "Other World" to which Sir Orfeo ventures, is full of shadow customs, which have all of the form of the real-world customs to which Orfeo is familiar, but none of the function. They are just empty mimicries, devoid of real reason or understanding. The fairies, for all of their power, are pathetic, due to their lack to creativity and understanding of even the most basic motives and necessities of their behavior. So, the ultimate message of Sir Orfeo may be that humans, with all of our weaknesses, shortcomings and sins are better off than the powerful pre-Christian specters.