Italian architect, designer, and sculptor. He made three pairs of bronze doors: for the Porta Regia of the west front (1180—destroyed), the Porta di San Ranieri (c.1180) of the south transept at Pisa Cathedral, and for the west portal of Monreale Cathedral, Sicily (the last signed and dated 1186). He may have designed the campanile (or ‘leaning tower’) of Pisa (1174–1271). His part in the creation of the Duomo and Baptistery at Pisa is uncertain, and the subject of much debate.
Dizionario biografico degli italiani (1969)