Italian sculptor, son or nephew of Gian Giacomo della Porta (active 1513, d. ca. 1554, Genova). He was part of an Italian family of sculptors, stone masons and architects, active from the 15th century to the 17th. Originally they came from Porlezza on Lake Lugano, but they were active in the masons' lodges of Milan Cathedral and the Certosa di Pavia from the 1470s. Around 1500, Antonio della Porta set up a workshop in Genoa, where he collaborated with, among others, his nephew Pace Gagini of the Gagini family of sculptors and stone masons, producing sculpture that was exported to France. Guglielmo must have learnt his craft in Milan in the 1520s, at the time when Gian Giacomo was a member of the stonemasons' lodge of Milan Cathedral. Around 1530, in Genoa, Guglielmo must have met Perino del Vaga, who had a decisive influence on his style. With Gian Giacomo and Niccolò da Corte he worked on the baldacchino, completed in 1532, in the chapel of San Giovanni Battista, Genoa Cathedral. A number of reliefs of prophets on the socles of the baldacchino have been identified as Guglielmo's earliest works. As an independent sculptor, Guglielmo worked on several figures for the Cybo monument, a commission begun in 1533. Guglielmo's contributions to this monument are the figures of Giuliano Cybo (rediscovered in 1955) and of Abraham. According to Vasari, Guglielmo moved to Rome in 1537. However, his name does not feature on any documents there until 1546. Initially, he worked with Perino del Vaga and produced designs for stucco decorations, now lost, for the Cappella Massimi in Trinità dei Monti. The Farnese family commissioned him to restore antique sculptures, including the Farnese Hercules, which he restored in 1547 after its discovery by Cardinal Alessandro Farnese in 1540. In the same year he was nominated 'Piombatore Apostolico' - officially in charge of the lead used for making papal bulls - in succession to Sebastiano del Piombo, and thereafter is known as Fra Guglielmo della Porta. From c. 1544 Guglielmo was patronized by the Farnese pope Paul III, producing bronze and marble busts of him. Guglielmo was probably commissioned to construct the funerary monument to Paul III in 1547. In 1575 his ambitious free-standing tomb was temporarily erected in the nave of St Peter's, but by 1588 it had been dismantled and reconstructed in a different form, in a recess in a crossing pier. Guglielmo was probably responsible for at least the design of a number of other funerary monuments in Rome. Guglielmo's numerous bronze sculptures include 16 mythological reliefs after Ovid and are held in several collections (e.g. Judgement of Paris, Kunsthistorisches Museum, Vienna; Bacchanalian Feast, Metropolitan Museum of Art, New York) as well as crucifixes and representations of scenes from the Passion. The Farnese Table (Metropolitan Museum of Art, New York), which was once attributed to Giacomo da Vignola, is probably by Guglielmo. Guglielmo also produced some architectural designs for San Silvestro al Quirinale in Rome. An outline for a treatise on architecture shows that Guglielmo had a thorough knowledge of architectural matters. //