Lancelot du Lac is a Knight of the Round Table and first knight to King Arthur. Some claim he had an affair with Guinevere, but Shining Knight thinks that's a lie. Others claim he is a past incarnation of Warlord.
Lancelot is based on the mythical knight, and like other Arthurian characters, has not been portrayed consistently in all the years of adaptations. His appearance and demeanor has fluctuated between a noble knight, a warrior eager for battle, and the man whose love for Guinevere doomed Arthur.