Chretien's works include four major poems in rhyming eight-syllable couplets: Erec and Enide (c. 1170, Cliges (c. 1176), Yvain, and Lancelot (both written simultaneously between 1177 and 1181). The last thousand lines of Lancelot were written by Godefroi de Lagny, apparently by arrangement with Chretien. Another poem, Perceval le Gallois, was composed for Phillip, Count of Flanders after 1181, to whom Chretien was attached in his last years. However, Chretien only wrote the first 9000 lines of the 32,000 verses of this work. To him are also attributed two lesser works: the pious romance Guillaume d'Angleterre (an attribution that is no longer believed), and Philomena, the only one of his four poems based on Ovid's Metamorphoses that has survived.
The immediate and specific source for his romances is of deep interest to the student; unfortunately, he has left us in the dark as to what these were. He speaks in the vaguest way of the materials he used, and there is no evidence that he had any Celtic written sources. Geoffrey of Monmouth or Wace might have supplied some of the names, but neither author mentioned Erec, Lancelot, Gornemant and many others who play an important role in Chretien's narratives. One is forced to guess about Latin or French literary originals which are now lost, or upon continental lore that goes back to a Celtic source. It is the same problem that faces the student in the case of Beroul, an Anglo-Norman who wrote about 1150. However, Chretien found his sources immediately at hand, without much understanding of its primitive spirit, but appreciating it as a setting for the ideal society dreamed of, although not realized, in his own day. And Chretien's four romances together form the most complete expression from a single author of the ideals of French chivalry.
A French narrative poet of the twelfth century had three categories of subject matter from which to draw his material: The Matter of France, or legends of that country foremost of which was the battle of Roncevaux -- in which the sensechal Roland fights a doomed final stand -- as well as other legends surrounding the court of King Charlemagne; The Matter of Rome, or legends culled from Antiquity about Thebes, Alexander the Great, Troy and Aeneas; and lastly The Matter of Britain, legends connected with King Arthur and other Celtic heroes. It is to Chretien's credit that he was alive to literary interest of this material when adapted to suit the taste of his French readers; to his greater credit of giving to the somewhat crude folk-lore a polish and elegance, which is inseparably associated with the Arthurian legends in modern literature.
This article was based on an essay by W. W. Comfort, published in 1914.