(1624–86). Italian Baroque sculptor and stuccoist. From 1645 he was assistant in Rome to Algardi and then for many years chief assistant to Bernini, carrying out numerous statues and reliefs to his designs. Among his many contributions to Bernini's output are the colossal statue of the River Danube (1650–1) on the Four Rivers Fountain in Piazza Navona and the Angel Carrying the Column (1668–9) on the Ponte S. Angelo. His independent works include a marble relief of The Death of S. Cecilia (1662–6; Rome, S. Agnese in Agone) and the monument to Lady Jane Cheyne (1671; London, Chelsea Old Church), as well as the magnificent stucco decorations surrounding Gaulli's frescoes of 1672–9 on the ceiling of the Gesù, Rome.
From The Oxford Companion to Western Art in Oxford Reference.