It was not chance which took Bramante, Raphael, and Michelangelo to Rome. They went because the papal court, pursuing its policy of maintaining the Papacy at the head of Christendom by means of culture, summoned them to come. Rome never produced great artists. She never was artistic, any more than she had been spiritual. But just as in earlier times she had drawn spiritual forces to herself and used them, so now she attracted to herself and used the artistic forces of Italy. She had been making ready for years; step by step as she had become more secular, she had also become more artistic, more intellectual. For seventy years every Pope contributed to this end. Eugenius IV employed distinguished humanists as his secretaries, and invited the most notable painters and sculptors to Rome. Nicholas V conceived the splendid scheme of making Rome the mistress of the world's culture. Pius II, AEneas Sylvius Piccolomini, was the most eminent man of letters of his age. Paul II was a virtuoso in objects of art and increased the grandeur of the papal court. Sixtus IV improved the city, built the Sistine Chapel, and employed Botticelli, Perugino, Signorelli, Ghirlandaio, and Rosselli to decorate it. Innocent VIII brought Mantegna from Padua and Pinturicchio from Perugia to embellish the Vatican palace. Pope Borgia made Pinturicchio his court painter; and that charming master decorated the papal apartments in the Vatican with the great bull of the Borgia crest, and with portraits of the Pope's children and (so Vasari says) of the lovely Giulia Farnese as the Virgin with the Pope worshipping her.