In later legend, the Holy Grail becomes an object of consecrated search, and the leading role in the quest is assigned to Sir Galahad, one of Arthur's knights. Many other knights set out to find the sacred chalice, but the quest is realized only by Sir Bors, in addition to Parzival and Galahad.
Many features of the Grail story, notably the hero and the magic vessel, are now regarded as arising from a Celtic saga that was Christianized into a vehicle for moral and religious instruction. The development of this legend was as follows. Chrétien de Troyes, the 12th-century French poet, left at his death an unfinished poem, Perceval le Gallois, that was continued by other writers. On the same source as that of Chrétien's romance or on the poem itself, the 13th-century German epic poet Wolfram von Eschenbach founded his Parzival, one of the finest treatments of the Grail theme. In the 15th century the English writer and translator Sir Thomas Malory embodied the quest of the sacred chalice in his Morte d'Arthur.
In the 19th century the Grail legend was used by the English poet Alfred, Lord Tennyson in his Idylls of the King and by the German composer Richard Wagner in his music drama Parsifal.