In 1454, he signed a contract for the "Polyptych of Saint Augustine" in the church of Sant'Agostino in Sansepolcro. The central panel of this polyptych is lost, and the four panels of the wings, with representations of saints, are now scattered around the world. A few years later, summoned by Pope Nicholas V, he moved to Rome, where he executed frescoes in the Basilica di Santa Maria Maggiore, of which only fragments remain. Two years later he was again in the Papal capital, painting frescoes in the Vatican Palace, which have since been destroyed.