Sir Orfeo is found in three MSS.: (1) the Auchinleck MS. (1325-1350), a famous Middle English miscellany now in the Advocates' Library, Edinburgh; (2) British Museum MS. Harley 3810 (fifteenth century); (3) Bodleian MS. Ashmole 61 (fifteenth century). Our text follows the Auchinleck MS., with ll. 1-24 and ll. 33-46 supplied from the Harleian MS. The critical text of O. Zielke, Breslau 1880, reproduces the MSS. inaccurately.
The story appears to have been translated from a French source into South-Western English at the beginning of the fourteenth century. It belongs to a group of 'lays' which claim to derive from Brittany, e.g. Lai le Freine, which has the same opening lines (1-22); Emaré; and Chaucer's Franklin's Tale.
The story of Orpheus and Eurydice was known to the Middle Ages chiefly from Ovid (Metamorphoses x) and from Virgil (Georgics iv). King Alfred's rendering of it in his Boethius is one of his best prose passages, despite the crude moralizing which makes Orpheus's backward glance at Eurydice before she is safe from Hades a symbol of the backslider's longing for his old sins. The Middle English poet has a lighter and daintier touch. The Greek myth is almost lost in a tale of fairyland, the earliest English romance of the kind; and to provide the appropriate happy ending, Sir Orfeo is made successful in his attempt to rescue Heurodis. The adaptation of the classical subject to a mediaeval setting is thorough. An amusing instance is the attempt in the Auchinleck MS. to give the poem an English interest by the unconvincing assurance that Traciens (which from 'Thracian' had come to mean 'Thrace') was the old name of Winchester (ll. 49-50).
<[We redyn ofte] and fynde ywryte,
As clerkes don us to wyte,
The layes that ben of harpyng
Ben yfounde of frely thing.
Sum ben of wele, and sum of wo, 5
And sum of ioy and merthe also;