The son of a butcher, Agnolo di Cosimo Mariano di Tori, better known by his nickname Agnolo Bronzino, was born on November 17, 1503, in Monticelli, then a suburb of Florence. From 1515 to 1518 he was apprenticed to the painter Jacopo Pontormo (1494–1557), and by the early 1520s he had gained some independence as a collaborator in the elder master's workshop. The friendship and professional association between Pontormo and Bronzino, who were relatively close in age, continued for almost four decades.