St. Peter’s Basilica

St. Peter’s Basilica is the central place of the Roman Catholic Church. From its inception, it took 225 years to complete. No fewer than sixteen architects were responsible for it, under the patronage of twenty-two popes. Nevertheless, the great building presents a degree of integrity, of harmony (perhaps helped by the mellowing passage of the centuries) that might seem improbable given its heterogeneous and sometimes philosophically conflicting sources; that ultimate unity of form and detail is in itself no small architectural feat.

In a.d 323, the first Christian Roman, emperor, Constantine the Great (died 337), commissioned a magnificent basilica on the Vatican Hill, south of the River Tiber. It was built with difficulty on the sloping site, its altar supposedly above the spot where St. Peter was believed to have been buried around a.d. 64, and dedicated to him. Twelve centuries passed from the building of Constantine’s basilica to the first phase of its demolition.

Between 1309 and 1377, for political reasons, the papal residence was at Avignon, France. Rome became derelict; according to some sources, packs of wolves roamed the streets. Its churches were neglected, and the old St. Peter’s descended into decay, its walls leaning and its frescoes encrusted with dust and grime. With the popes again in residence, around the middle of the fifteenth century Rome succeeded Florence as the center of the Italian Renaissance, and in 1452 Pope Nicholas V (reigned 1447–1455) commissioned the architect Bernardo Rossellino (1409–1464) to build a new apse for St. Peter’s west of the old one. Rossellino, who had already restored the church of San Francesco, Assisi, and many other buildings in Italy, proposed to surround the choir and transept, continuing the elongated Latin-cross plan. But only the tribune and foundations had been built when Nicholas V died and work stopped. Pope Paul II (1464–1471) passed the project to Giuliano da Sangallo in 1470, but none of the subsequent three popes pursued it.

Early in 1505 the warrior-pope Julius II (1505–1513) was considering what form his own tomb might take. The sculptor Michelangelo Buonarotti designed an imposing monument, but it called for an appropriate setting. Julius decided to rebuild St. Peter’s, and late in 1505, a competition was held for the design. The winner was Donato Bramante, who, inspired by the ancient Pantheon in Rome, proposed a Greek cross (all of the arms of which are equal), with towers at the corners and a central dome raised on a drum. Julius laid the foundation stone on 18 April 1506. Despite the theological and esthetic arguments for a centrally planned church, the Greek cross was impractical for the Roman liturgy and thus unacceptable to the clergy. Bramante lengthened one arm to form the traditional Latin cross. Much of Julius II’s money was diverted to wars with the French, and when his architect died in 1514, only the four main piers of St. Peter’s were completed. They determined all further developments.

Julius’s successor, the Borgia Leo X (1513–1521), commissioned Rafaello da Urbino, assisted by Giuliano da Sangallo and Fra Giocondo da Verona. The latter two modified Bramante’s plan to a slightly elongated central nave with three aisles on either side. They died in 1516 and 1515, respectively, and Rafaello simplified their plan, seemingly to little effect. After his death in 1520 the new architects, Antonio da Sangallo the Elder, Baldassarre Peruzzi, and Andrea Sansovino, “without fixed plans and [attempting] all manner of experiments,” revived arguments about a Greek cross versus a Latin cross. Seething conflicts in southern Europe impeded the work until Pope Paul III (1534–1549) engaged the architect Antonio da Sangallo the Younger, who revived Bramante’s plan. Da Sangallo died in 1546. The following year Paul III offered the post of Prefect of Works to the 71-year-old Michelangelo, who accepted but refused payment for his work. He adapted Bramante’s original plan, reducing the floor area by 40 percent, and started designing the three apses and the dome, which he made possible by strengthening the central piers. By 1564, when the great artist died, one apse and the drum of the dome as high as the entablature were completed. He was succeeded by Pirro Ligorio (better remembered as a coin counterfeiter than as an architect) and Giacomo da Vignola.

Pope Gregory XIII (reigned 1572–1585) next placed Giacomo della Porta in charge of St. Peter’s. Assisted by Domenico Fontana, he subtly altered Michelangelo’s design for a hemispherical dome, building a taller, more pointed structure based on Brunelleschi’s Florence duomo. Work began in 1587, and the dome was completed under the patronage of Sixtus V (1585–1590). His successor, Gregory XIV (1590–1591), commissioned the lantern. Working for Paul V (1605–1621), Carlo Maderna gave the final building the form of a Latin cross by extending the nave to the east by building three more bays. He also won a 1607 competition for the design of the main facade, completed in 1626, and added an extra bay at each end to support bell towers. Pope Urban VIII solemnly consecrated the church on 18 November 1626.

But the project was not yet finished. Only one bell tower was built (and later demolished), to a 1637 design of Gian Lorenzo Bernini, the last architect to contribute to St. Peter’s. For Pope Alexander VII (1655–1667), Bernini put final touches to the sumptuous basilica (the baldachin beneath the dome and St. Peter’s Chair) and between 1656 and 1660 laid out the vast elliptical piazza, whose colonnaded arms open to welcome all to the bosom of Mother Church.

In 1984, the U.S. Catholic organization the Knights of Columbus collaborated with Reverenda Fabrica di San Pietro to restore the main facade. St. Peter’s Basilica, with a floor area of 3.7 acres (1.5 hectares), was the largest church in Christendom until 1989, when its size was exceeded by the mimetic and extravagant Church of Our Lady of Peace (commenced 1986) in Yamoussoukro, Côte d’Ivoire, Africa.