Piombo, Sebastiano del byname of Sebastiano Luciani (c. 1485, Venice [Italy]. July 21,1547, Rome, Papal States [now in Italy]), Italian painter who tried to combine the rich colours of the Venetian school with the monumental form of the Roman school. While he was in Venice, Sebastiano was a pupil of Giorgione, whose influence is apparent in his work. (1510; National Gallery, London). In 1511 Sebastiano went to Rome, where the Sienese banker Agostino Chigi had engaged him to decorate his newly built Villa Farnesina. Shortly after completing this commission, Sebastiano settled permanently in Rome, where he became a member of Raphael's circle of artists andsoon showed himself to be a notable portraitist. About 1515 Sebastiano came under the influence of Michelangelo and began collaborating with that artist. From drawings and cartoons by Michelangelo he executed his best-known work, San Pietro in Montorio, Rome) . Michelangelo's opinion of him was so high that he thought by correcting his rather dull draftmanship, he could make Sebastiano the best painter in Rome. In his Roman work Sebastiano combined the warm colouring of the Venetian school with the anatomical clarity and firm sculptural drawing probably resulting from his association with Michelangelo. From 1519 to 1530 Sebastiano had an unparalleled reputation in Rome as a portraitist. In 1531 Pope Clement VII bestowed upon Sebastiano the lucrative post of keeper of the papal seal. During the last 17 years of his life this economic security seems to have been a significant contributing factorin Sebastiano's limited production of pictures.