Oliver Huckel (1864-1940) was an American clergyman and author, best known for nine books on Wagner's operas and articles focusing on the religious identity of Benjamin Franklin. Parsifal is Wagner's last opera loosely based on Wolfram von Eschenbach's Parzival, the 13th century epic poem of the Arthurian knight Parzival (Percival) and his quest for the Holy Grail, and on Chrétien de Troyes' Perceval, the Story of the Grail.