The genre of Le Morte d'Arthur is Arthurian Romance. It is somewhat unusual for an entire genre to center on a single character, but Arthurian Romance is an exception because King Arthur was such a popular legendary figure. Particularly in France and Britain between the 12th and 15th centuries, writers built not only on the folklore and legends about Arthur but also on one another's writing about him. Arthur himself was less of a developed character than the central figure drawing together a set of stories about chivalry.
Malory and other writers of Arthurian Romance (such as Chrétien de Troyes, Marie de France, and even Geoffrey Chaucer) did different things with the same source material, but books and poems in this genre typically share a sense of nostalgia for a chivalric code that is lost to the world. They also often include bawdy and slapstick comedy, such as the scene where Launcelot mistakenly sleeps with Elaine of Corbin instead of Guenever. These comedic moments contrast with exaggerated accounts of Arthurian knights' greatness and skill on quests and on the battlefield. Arthurian Romance is often deeply Christian. Frequently, the knights' bitterest enemies are Muslim.
The Arthur-Guenever-Launcelot love triangle is almost always incorporated into Arthurian Romance. Other plot lines vary from one book to another. Even within Malory's book, contradictory plot points are not treated as a problem to explain away. For example, there are two different origin stories in Malory's book for Arthur's sword. This is because Malory was doing something rather new in drawing together many tales of King Arthur's court into one epic narrative. The two different stories about the sword are not original to Malory's narrative. Some accounts focus on one origin story or the other, and still others hold that there are two separate swords. Malory allows both to be Excalibur. What seems to matter to him more than the exact details of Arthurian "history" is the chivalric ethos and the idea that the world has changed since the time of Arthur. This attitude is in keeping with other Arthurian Romances.
Still, Malory is invested in the idea that there is some real historical basis for this lost chivalric ethos. In Volume 2, Book 17, Chapter 23, Galahad achieves the Sangreal. Sir Bors returns to Camelot, where he tells the story specifically so that historians might write it down. The chapter ends with an interjection from the narrator about the book's source material:
Thus endeth the history of the Sangrail, that was briefly drawn out of French into English, the which is a story chronicled for one of the truest and the holiest that is in this world, the which is the xvii. book.
This interjection reminds the reader that Malory is not presenting a work of fiction. At least, fiction is not what he is pretending to present. Although Malory is certainly taking creative license with his source material, he claims that the story of the Sangreal was translated into English from French and has simply been "chronicled" for Book 17. Framing himself as a "chronicler," Malory suggests that there is at least a kernel of truth in the story. He hopes that his 15th century readers will feel a connection to the Sangreal and to Galahad's excellent chivalry, and that they will adopt a love for this chivalry as their own heritage.
