The Lady of the Lake is the name of several related characters who play parts in the Arthurian legend. These characters' roles include giving King Arthur his sword Excalibur, enchanting Merlin, and raising Lancelot after the death of his father. Different writers and copyists give her name variously as Nimue, Viviane, Elaine, Niniane, Nivian, Nyneve, Nimueh and other variations.
Alfred Tennyson adapted several stories of the Lady of the Lake for his poetic cycle Idylls of the King. He splits her into two characters; Viviane is a deceitful villain who ensnares Merlin, while the Lady of the Lake is a benevolent figure who raises Lancelot and gives Arthur his sword. Nimue appears in T. H. White's The Once and Future King as Merlin's love interest. True to the legend she traps Merlin in a cave, but Merlin does not convey it as negative, and even refers to it as a vacation.