Nimue. The Lady of the Lake is an enchantress in the Matter of Britain, the body of medieval literature and legend associated with King Arthur.
She plays a pivotal role in many stories, including giving Arthur his sword Excalibur, enchanting Merlin, and raising Lancelot after the death of his father. At least two different sorceresses bearing the title the Lady of the Lake appear as separate characters in some versions and adaptations since the Post-Vulgate Cycle and consequently Le Morte d'Arthur.
Although today the Lady of the Lake is best known as Nimue, Vivian, and Vivien, different medieval authors and copyists have also given the character various names, including Nimane, Nimanne / Niv en e / Vivienne, Nimian e, Nymenche, Nin eve, Niniane, Niviana, and Ui ane, among other variations, including alternate spellings with the letter i written as y. The most primitive French form might be Niniane. The name Nimue, in which the letter e can be written as ë or è, has been popularized by Thomas Malory's Le Morte d'Arthur and itself has several variations: in William Caxton's edition, her name appears as Nymue, Nyneue and Nynyue, but it had been rather Nynyve and Nenyve in Malory's original Winchester Manuscript.
Even though Nymue, with the m, appears only in the Caxton text, Nimue is perhaps the most common name of the character as this was the only version of Le Morte d'Arthur published