Le Morte d'Arthur (originally spelled Le Morte Darthur, Middle French for "the death of Arthur") is a reworking of existing tales by Sir Thomas Malory about the legendary King Arthur, Guinevere, Lancelot, Merlin, and the Knights of the Round Table. Malory interprets existing French and English stories about these figures and adds original material (e.g., the Gareth story).
Le Morte d'Arthur was first published in 1485 by William Caxton, and is today one of the best-known works of Arthurian literature in English. Many modern Arthurian writers have used Malory as their principal source, including T. H. White in his popular The Once and Future King and Tennyson in The Idylls of the King.
Sir Thomas Malory was a knight in the fifteenth century, who, while imprisoned, compiled the collection of tales we know as Le Morte D'Arthur, translating the legend of King Arthur from original French tales such as the Vulgate Cycle.