Hero of Arthurian legend .
His childlike innocence protected him from worldly temptation. In Chrétien de Troyes's 12th-century Le Conte du Graal , Perceval visits the castle of the wounded Fisher King and sees the Grail , but he fails to ask about it and therefore fails to heal the Fisher King. He subsequently sets out in search of the Grail and grows spiritually. In later Grail legend he was displaced by Galahad as the hero of the Grail quest but continued to play an important role. His story was told in Wolfram von Eschenbach's 13th-century Parzifal , which provided the basis for Richard Wagner 's opera Parsifal (1882).