The Morte Darthur, parts seven and eight

Le Morte d'Arthur (originally spelled Le Morte Darthur, ungrammatical Middle French for "The Death of Arthur") is a 15th-century Middle English prose reworking by Sir Thomas Malory of tales about the legendary King Arthur, Guinevere, Lancelot, Merlin and the Knights of the Round Table—along with their respective folklore. In order to tell a "complete" story of Arthur from his conception to his death, Malory compiled, rearranged, interpreted and modified material from various French and English sources. Today, this is one of the best-known works of Arthurian literature. Many authors since the 19th-century revival of the legend have used Malory as their principal source.

(Source: Wikipedia)