He was born Pietro Berrettini, but is primarily known by the name of his native town of Cortona in Tuscany. He worked mainly in Rome and Florence. He is best known for his frescoed ceilings such as the vault of the "salone" or main salon of the Palazzo Barberini in Rome and carried out extensive painting and decorative schemes for the Medici family in Florence and for the Oratorian fathers at the church of Santa Maria in Vallicella in Rome. He also painted numerous canvases. Only a limited number of his architectural projects were built but nonetheless they are as distinctive and as inventive as those of his rivals.