[irrelevant title]

It's true that the name "Lancelot" first appears in the work of a French author named Chrétien de Troyes in the late 12th Century (as does the motif of adultery between Lancelot and Guinevere), but there's also a parallel German tradition about a knight named "Lanzelet" that arose at around the same time, and both of them show clear signs of derivation from earlier Welsh traditions in which most of the key elements of Lancelot's biography – being raised by water fairies, the entering of three consecutive tournaments in three different disguises, etc. – are frequently attributed to other, similar figures.

Meanwhile, the specific version of Lancelot who most often appears in modern renditions of the Arthurian mythos isn't any of these, but rather, the product of an attempt to reconcile these and other sources into a unified narrative by an English author pseudonymously known as Thomas Malory some three hundred years later.