Rosso Fiorentino, byname of Giovanni Battista di Jacopo  (b. March 8, 1494, Florence [Italy]—d. Nov. 14, 1540, Fontainebleau, France), Italian painter and decorator, an exponent of the expressive style that is often called early, or Florentine, Mannerism, and one of the founders of the Fontainebleau school. Rosso received his early training in the studio of Andrea del Sarto, alongside his contemporary Jacopo da Pontormo. Scholars have argued that he was influenced as much by Pontormo as by Sarto. The earliest works of these two young painters combined influences from Michelangelo ...