https://en.wikipedia.org/wiki/PerlesvausPerlesvaus, also called Li Hauz Livres du Graal (The High Book of the Grail), is an Old French Arthurian romance dating to the first decade of the 13th century. It purports to be a continuation of Chrétien de Troyes' unfinished Perceval, the Story of the Grail, but it has been called the least canonical Arthurian tale because of its striking differences from other versions.
Perlesvaus presents itself as a translation of a Latin source found in Avalon[1] as narrated by the mysterious Josephus (possibly the same as the scribe monk Josephus from the Estoire de Merlin[2]). It follows a highly complex[3] narrative chronicling the progress of various Knights of the Round Table in their quest for the Holy Grail.
The work begins by explaining that its main character, Perceval, did not fulfill his destiny of achieving the Grail because he failed to ask the Fisher King the question that would heal him, events related in Chrétien's work. The author soon digresses into the adventures of knights like Lancelot and Gawain, many of which have no analogue in other Arthurian literature. It is also notably both darker in tone and significantly more brutal and violent than a usual Arthurian romance.[4][5]
Often events and depictions of characters are thoroughly at odds with other versions of the story. For instance, while later literature depicts Loholt as a good knight and illegitimate son of King Arthur, in Perlesvaus he is apparently the legitimate son of Arthur and Guinevere, and he is slain treacherously by Arthur's seneschal Kay, who is elsewhere portrayed as a boor and a braggart but always as Arthur's loyal servant (and often, foster brother).[6] Kay is jealous when Loholt kills a giant, so he murders him to take the credit. This backfires when Loholt's head is sent to Arthur's court in a box that can only be opened by his murderer. Kay is banished, and joins with Arthur's enemies, Brian of the Isles and Meliant. Guinevere expires upon seeing her son dead, which alters Arthur and Lancelot's actions substantially from what is found in later works.
https://www.gutenberg.org/ebooks/750
https://archive.org/details/evansthehighhistoryoftheholygr