Guinevere /ˈɡwɪnᵻvɪər/, often written as Guenevere or Gwenevere, was the wife of King Arthur of legend. In medieval romances, one of the most prominent story arcs is Queen Guinevere's love affair with her husband's chief knight, Lancelot. This story first appeared in Chrétien de Troyes's Lancelot, the Knight of the Cart and became a motif in Arthurian literature, starting with the Lancelot-Grail of the early 13th century and carrying through the Post-Vulgate Cycle and Thomas Malory's Le Morte d'Arthur. Guinevere and Lancelot's betrayal of Arthur preceded his eventual defeat at the Battle of Camlann by Mordred.