The story of “The Demon Pope” is based upon a legend of a compact between a Pope and the devil. It is believed that Gerbert, who later became Pope Silvester II, sold his soul to Satan in order to acquire a knowledge of physics, arithmetic and music. The fullest account of this legend will be found in J. J. Dollinger’s _Fables Respecting the Popes of the Middle Ages_ (Engl. Translation, 1871). _The History of the Devil and the Idea of Evil_ by Paul Carus (1900) contains the following passages on this legend: “An English Benedictine monk, William of Malmesbury, says of Pope Sylvester II., who was born in France, his secular name being Gerbert, that he entered the cloister when still a boy. Full of ambition, he flew to Spain where he studied astrology and magic among the Saracens. There he stole a magic-book from a Saracen philosopher, and returned flying through the air to France. Now he opened a school and acquired great fame, so that the king himself became one of his disciples. Then he became Bishop of Rheims, where he had a magnificent clock and an organ constructed. Having raised the treasure of Emperor Octavian which lay hidden in a subterrenean vault at Rome, he became Pope. As Pope he manufactured a magic head which replied to all his questions. This head told him that he would not die until he had read Mass in Jerusalem. So the Pope decided never to visit the Holy Land. But once he fell sick, and, asking his magic head, was informed that the church’s name in which he had read Mass the other day was ‘The Holy Cross of Jerusalem.’ The Pope knew at once that he had to die. He gathered all the cardinals around his bed, confessed his crime, and, as a penance, ordered his body to be cut up alive, and the pieces to be thrown out of the church as unclean. “Sigabert tells the story of the Pope’s death in a different way. There is no penance on the part of the Pope, and the Devil takes his soul to hell. Others tell us that the Devil constantly accompanied the Pope in the shape of a black dog, and this dog gave him the equivocal prophecy.