About the Arthurian legends (from Wikipedia):
Le Morte d’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.
Written in prison, Le Morte d’Arthur was first published in 1485 at the end of the medieval English era by William Caxton, who changed its title from the original The Whole Book of King Arthur and of His Noble Knights of the Round Table (The Hoole Book of Kyng Arthur and of His Noble Knyghtes of The Rounde Table). Until the discovery of the Winchester Manuscript in 1934, the 1485 edition was considered the earliest known text of Le Morte d’Arthur and that closest to Malory’s original version. Modern editions under various titles are inevitably variable, changing spelling, grammar and pronouns for the convenience of readers of modern English, as well as sometimes abridging or revising the material.