The realistic tendency exhibited by Masaccio grew more prominent in Paolo Uccello, who was evidently influenced by sculpture, especially by Donatello. In some of his most important frescoes, those in Sta. Maria Novella, representing the history of the Creation, and the figure of John Hawkwood in Sta. Maria del Fiore,[149] the very colouring, grey upon grey, aims at producing the effect of sculpture. This painter’s study of perspective made him exaggerate that branch of his art. The austerity of Andrea dal Castagno’s style is not softened by the colouring. The repulsive expression of his group of St. John and St. Francis in Sta. Croce supports the legend of the murder of Domenico Veneziano, which has adhered to Andrea’s name till our own day, though he died four years before his supposed victim.[150] The most important works he has left are the figures of sibyls and of famous men, executed in a hall of the villa formerly belonging to the Pandolfini at Legnaia, but now removed to the National Museum at the Palace of the Podestà. The characteristic figures, among whom are Nicola Acciaiuolo and Pippo Spano, produce a great effect. Neither Andrea nor Uccello seems to have been employed by the Medici, who did, however, engage Domenico Veneziano, Andrea’s fellow-worker on the lost frescoes in Sta. Maria Nuova, a painter much influenced by Fra Angelico. The repeated occurrence of the Medici’s patron saints, Cosmo and Damian, in pictures of which the origin cannot be clearly traced, points to the conclusion that they were commissions from the family or their friends. But the painter most highly favoured by Cosimo and his sons was Fra Filippo Lippi, whose manners and conversation were as great a scandal to the Carmelite order as Fra Angelico’s whole life was an ornament to that of St. Dominic. Disorderly, loose in morals, always in difficulties and need of money, he yet gained patrons by his undeniable talent, which unites force and animation to Angelico’s intensity of feeling. Lippi’s grouping and composition is various, free, and rich, showing a realistic study of nature. He worked a great deal for the Medici, who made presents of his pictures to the Pope and King Alfonso, and procured him commissions abroad. His greatest work, the frescoes in the chapel in the choir of the Collegiate Church of Prato, was finished for the Provost Carlo de’ Medici, whose likeness may be seen in the representation of the burial of St. Stephen. It was through Cosimo, who had many connections in Umbria, that Fra Filippo went to Spoleto, where he executed in the cathedral the scenes from the history of the Madonna which were finished after his death in 1469 by his assistant Fra Diamante.