Vignola, Giacomo Barozzi da (1507–1573)

Italian architect, the leading architect in Rome after the death of Michelangelo. He is largely remembered for his architectural textbook Regole delle cinque ordini/On the Five Orders (1562). He appears to have designed much of the complex plan for the Villa di Papa Giulio, Rome (1551–55). In 1567 he succeeded Michelangelo, whose work he followed meticulously, as architect to St Peter's, Rome.

His first important work was the completion of Palazzo Farnese Capravola (1550), from designs by Baldassare Peruzzi. He worked in France 1541–43. He collaborated on the Villa di Papa Giulio with Bartolommeo Ammanati and Giorgio Vasari. The Gesù church in Rome, another of Vignola's highly influential designs, was built 1568–75 for the Jesuits.

The Regole delle cinque ordini/On the Five Orders became an architect's handbook and is considered one of the most important books ever written on architecture.