Breton lai

A Breton lai, also known as a narrative lay or simply a lay, is a form of medieval French and English romance literature. Lais are short (typically 600–1000 lines), rhymed tales of love and chivalry, often involving supernatural and fairy-world Celtic motifs. The word "lay" or "lai" is thought to be derived from the Old High German and/or Old Middle German "leich", which means play, melody, or song, or as suggested by Jack Zipes in "The Oxford Companion to Fairy Tales", the Irish word "laid" (song).
Zipes writes that Arthurian legends may have been brought from Wales, Cornwall and Ireland to Brittany; on the continent the songs were performed in various places by harpists, minstrels, storytellers. Zipes reports the earliest recorded lay is Robert Biker's Lai du Cor, dating to the mid- to late-12th century.
The earliest of the Breton lais to survive is probably "The Lais of Marie de France", thought to have been composed in the 1170s by Marie de France, a French poet writing in England at Henry II's court between the late 12th and early 13th centuries. From descriptions in Marie's lais, and in several anonymous Old French lais of the 13th century, we know of earlier lais of Celtic origin, perhaps more lyrical in style, sung by Breton minstrels. It is believed that these Breton lyrical lais, none of which has survived, were introduced by a summary narrative setting the scene for a song, and that these summaries became the basis for the narrative lais.
The earliest written Breton lais were composed in a variety of Old French dialects, and some half dozen lais are known to have been composed in Middle English in the 13th and 14th centuries by various English authors.
Breton lais may have inspired Chrétien de Troyes, and likely were responsible for spreading Celtic and fairy-lore into Continental Europe. An example of a 14th-century Breton lai has the king of the fairies carrying away a wife to the land of fairy.