CARAVAGGIO, POLIDORO CALDARA DA or , a celebrated painter of frieze and other decora tions in the Vatican. Polidoro's works, as well as those of his master, Maturino of Florence, have mostly perished, but are well known by the fine etchings of P. S. Bartoli, C. Alberti, etc. On the sack of Rome by the army of the Constable de Bourbon in 1527, Polidoro fled to Naples. Thence he went to Messina. He was murdered by an assistant, Tonno Calabrese, in Two of his principal paintings are a Crucifixion, painted in Messina, and "Christ bearing the Cross" in the Naples gallery.