Saint Peter's Church, Vatican City, principal and one of the largest churches of the Christian world. The present structure was built mainly between 1506 and 1626 on the original site of the Vatican cemetery and an early shrine to St. Peter. In the 4th cent. Emperor Constantine built the first church of St. Peter, a wood-roofed basilica, with transepts, five aisles, and an atrium. It was said to be built over the grave of St. Peter. Here Charlemagne and many other emperors and popes were crowned. In the 15th cent. Pope Nicholas V undertook the rebuilding of the choir and transepts after a design by Bernardo Rossellino. In 1452 the work was begun, and part of the choir was built.
Pope Julius II decided that the entire church should be rebuilt and in 1506 appointed Bramante as the architect. He appears to have originally planned a symmetrical Greek cross with a great dome over the center. Bramante was succeeded by Raphael (1514), Antonio da San Gallo (1520), and Michelangelo (1547), who completed the building up to the drum of the great dome. Giacomo della Porta modified the design and completed the dome.
Throughout the 16th cent. there was controversy over the final form in which the church would be built—the centralized Greek cruciform plan or the shape of a Latin cross. The problem was resolved in favor of the Latin cross plan, when Carlo Maderno added the nave and facade (1607–14). Unfortunately his additions obscured the dome. The church was dedicated by Urban VIII in 1626. Between 1629 and 1662 Bernini completed the great composition of St. Peter's, creating a forecourt preceded by a majestic elliptical piazza bounded by quadruple colonnades. The great obelisk of Heliopolis, brought to Rome by Caligula, was moved by Domenico Fontana, and now adorns the center of the piazza. A monumental avenue leading to the piazza was added by Mussolini. In 1996–99 the facade of the church was cleaned, and a dull straw color restored to lower portions of it.
The huge scale of all the elements of the interior prevents any accurate notion of its magnitude, and its effectiveness is chiefly due to the dome, which is 404 ft (123 m) high from the pavement. The interior diameter of the dome, 137 ft (42 m) is one of the largest in the world. Beneath it is the high altar covered by Bernini's superb bronze baldachino. At this altar only the pope may read Mass. The interior with its colored marbles, its sculptures, and its gilt and fresco decorations gives an effect of multicolored space.
See J. Lees-Milne, Saint Peter's (1967); T. and R. Bergere, The Story of St. Peter's (1967); I. Lavin, Bernini and the Crossing of St. Peter's (1968).