St. Peter's basilica, Rome

   The Mother Church of the Catholic faith, built over St. Peter's burial site. The history of St. Peter's basilica is quite complex. The first building to occupy the site was an Early Christian basilica with a Latin cross plan built during the reign of Emperor Constantine the Great. By the 15th century, the old structure had decayed considerably. Pope Nicholas V intended the reconstruction of its apse, for which new foundations were laid, but he died in 1455 and the project was abandoned. In 1503, Pope Julius II was elected to the throne and in 1506 he asked Donato Bramante to design a new basilica. Bramante's plan suggests that he intended to build a Greek cross structure with each arm flanked by smaller Greek crosses and towers at the corners. Since he only rendered half the cross, some believe that the plan only shows the basilica's choir to which a long nave and aisles were to be attached. A medal by Cristoforo Caradosso, one of Bramante's assistants, shows that the architect wanted to surmount each of the crosses with a dome, the largest surrounded by a colonnade. The façade was to employ a classical vocabulary with a pedimented entrance. Bramante died in 1514 and was succeeded by Raphael and, in 1520, Baldassare Peruzzi also became involved in the project. Both masters provided a number of drawings intended to correct the short-comings of Bramante's design, including the inadequate size of the central piers that were to support the main dome. In 1527, the sack of Rome halted building activity. Then Antonio da Sangallo the Younger became involved, writing a memorandum that criticized Raphael's design. Building moved slowly, until 1546 when Sangallo died and Michelangelo volunteered to complete the building without pay. Michelangelo reverted to Bramante's original plan. He thickened the outer walls and central piers and simplified Bramante's distribution of space, creating a more unified and coherent design. He then added a double-columned portico to the entrance to give it greater definition. He used the colossal order, an Albertian feature, through-out, granting the structure a virile, robust appearance, not unlike the muscular figures in his paintings and sculptures. An imposing dome on a drum, completed after Michelangelo's death in 1564 by his pupil Giacomo della Porta, caps the structure.

   In 1605, Pope Paul V called for a competition for the conversion of St. Peter's from a central to a longitudinal church and the building of a new façade. The motivation for this was the declaration by the Council of Trent that the Latin cross plan was better suited for the rituals of the mass. Also, the pope wanted the basilica to cover the same ground as the old Early Christian structure that had stood earlier on the site. Carlo Maderno won the competition and, between 1606 and 1612, he carried out the building's restructuring. He added a three-bay nave, continuing some of Michelangelo's features to ensure a harmonious design. His façade follows the principles established by Giacomo da Vignola and Giacomo della Porta in the Church of Il Gesù, Rome (1568-1584), mainly the rapid progression from the outer bays to the main portal.

   Once completed, the pope decided to add towers at either end of the façade. This proved to be a disaster. Two outer bays were added to support the towers, but soon it was discovered that an underground spring would prevent a structurally sound construction. The project was abandoned, but the outer bays were left in place. These, unfortunately, ruined Maderno's well-planned proportions, a situation for which he has been severely and unjustly criticized. In the 1630s, Gian Lorenzo Bernini proposed the completion of the towers. With Urban VIII's approval, he erected the south tower, but again the underground spring caused problems and the new structure began to crack. Bernini was able to redeem himself after this major blow to his career when in 1656-1667 he built for Innocent X the piazza in front of the basilica, a space now used to hold the crowds who come to hear the pontiff speak from the papal balcony, its colonnades the symbol of the all-embracing arms of the Catholic Church.