Study for the Age of Bronze, 1637, Pen and brown ink, over black chalk, 9 3/16 x 6 3/4in. (23. 3 x 17. 2cm), Drawings, Pietro da Cortona (Pietro Berrettini) (Italian, Cortona 1596?1669 Rome), This rapid sketch of a Roman military triumph was intended for a fresco painting alluding to the theme of the 'Age of Bronze' in the Camera della Stufa of the Palazzo Pitti in Florence that Cortona began in 1637 for Ferdinando II de' Medici