The Lancelot-Grail, also known as the Prose Lancelot, the Vulgate Cycle, or the Pseudo-Map Cycle, is a major source of Arthurian legend written in French. It is a series of five prose volumes that tell the story of the quest for the Holy Grail and the romance of Lancelot and Guinevere. The major parts are early 13th century, but scholarship has few definitive answers as to the authorship. An attribution to Walter Map is discounted, since he died too early to be the author. This cycle of works was one of the most important sources of Thomas Malory's Le Morte d'Arthur.