Polidoro Caldara was born in Caravaggio, in what is now Lombardy. According to Vasari, whilst working as a labourer carrying the materials for the builders of the Vatican logge he ingratiated himself with the artists, and attracted the admiration of Maturino da Firenze, one of Raphael's main assistants in the ongoing decoration of the Vatican. He then joined Raphael's large workshop, in about 1517, and worked on the Raphael Rooms in the Vatican. He and Maturino then set up as painters of palace facades, usually in sgraffito, with considerable success until the sack of Rome by the army of Charles V under the command of Constable de Bourbon in 1527, in which Maturino was killed. Polidoro fled to Naples, and from there to Messina, where he was very successful. According to tradition, he was about to return from there to the mainland of Italy when he was robbed and murdered by an assistant, Tonno Calabrese, in 1543.