Percival is the Grail knight or one of the Grail knights in numerous medieval and modern stories of the Grail quest. Percival first appears in Chrétien de Troyes's unfinished "Percivale or Conte del Graal" (c. 1190). The incomplete story prompted a series of "continuations," in the third of which (c. 1230), by an author named Manessier, Percival achieves the Grail. (An analogue to Chrétien's tale is found in the thirteenth-century Welsh romance Peredur.)