St. Peter's Basilica in Rome

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The Papal Basilica of Saint Peter' , officially known in Italian as ' and commonly known as Saint Peter's Basilica, is a Late Renaissance church located within the Vatican City. Saint Peter's Basilica has the largest interior of any Christian church in the world.

St. Peter's is famous as a place of pilgrimage, for its liturgical functions and for its historical associations. It is associated with the papacy, with the Counter-reformation and with numerous artists, most significantly Michelangelo. As a work of architecture, it is regarded as the greatest building of its age.

At the heart of the basilica, beneath the high altar, is the Confessio or Chapel of the Confession, in reference to the confession of faith by St Peter, which lead to his martyrdom. Two curving marble staircases lead to this underground chapel at the level of the Constantinian church. The Confessio gives access to the tomb of St Peter.

The entire interior of St Peter's is lavishly decorated with marble, reliefs, architectural sculpture and gilding. The basilica contains a large number of tombs of popes and other notable people, many of which are considered outstanding artworks. There are also a number of sculptures in niches and chapels, including Michelangelo's Pieta. The central feature is a baldachin, or canopy over the Papal Altar, designed by Gianlorenzo Bernini. The sanctuary culminates in a sculptural ensemble, also by Bernini, and containing the symbolic Chair of St Peter.

One observer wrote: "St Peter's Basilica is the reason why Rome is still the center of the civilized world. For religious, historical, and architectural reasons it by itself justifies a journey to Rome, and its interior offers a palimpsest of artistic styles at their best..."

The American philosopher Ralph Waldo Emerson described St Peter's as "an ornament of the earth ....the sublime of the beautiful."


The Basilica of St. Peter is one of four Papal Basilicas or Major Basilicas of Rome the others being the Basilica of St. John Lateran, Santa Maria Maggiore and St. Paul outside the Walls. It is the most prominent building in the Vatican City. Its dome is a dominant feature of the skyline of Rome. Probably the largest church in Christendom, it covers an area of 2.3 hectares (5.7 acres). One of the holiest sites of Christianity in the Catholic Tradition, it is traditionally the burial site of its titular Saint Peter, who was one of the twelve apostles of Jesus and, according to Catholic Tradition, also the first Bishop of Antioch and later first Bishop of Rome, the first Pope. Although the New Testament does not mention Peter's martyrdom in Rome, Catholic tradition, based on the writings of the Fathers of the Church, holds that his tomb is below the baldachin and altar; for this reason, many Popes have, from the early years of the Church, been buried there. Construction of the current basilica, over the old Constantinian basilica, began on 18 April 1506. At length on 18 November 1626, Pope Urban VIII solemnly dedicated the church. It was of typical basilical Latin Cross form with an apsidal end at the chancel, a wide nave and two aisles on either side. It was over 103.6 m long, and the entrance was preceded by a large colonnaded atrium. This church had been built over the small shrine believed to mark the burial place of St. Peter. It contained a very large number of burials and memorials, including those of most of the popes from St. Peter to the 15th century. Like all of the earliest churches in Rome, both this church and its successor had the entrance to the east and the apse at the west end of the building. Since the construction of the current basilica, the name Old St. Peter's Basilica has been used for its predecessor to distinguish the two buildings.

The plan to rebuild

By the end of the 15th century, having been neglected during the period of the Avignon Papacy, the old basilica was in bad repair. It appears that the first pope to consider rebuilding, or at least making radical changes was Pope Nicholas V (1447–55). He commissioned work on the old building from Leone Battista Alberti and Bernardo Rossellino and also got Rossellino to design a plan for an entirely new basilica, or an extreme modification of the old. His reign was frustrated by political problems and when he died, little had been achieved. was the subject of a competition for which a number of entries remain intact in the Uffizi Gallery, Florence. It was the design of Donato Bramante that was selected, and for which the foundation stone was laid in 1506. This plan was in the form of an enormous Greek Cross with a dome inspired by that of the huge circular Roman temple, the Pantheon. Sangallo's main practical contribution was to strengthen Bramante's piers which had begun to crack.

Michelangelo's contribution

Michelangelo took over a building site at which four piers, enormous beyond any constructed since the days of Ancient Rome, were rising behind the remaining nave of the old basilica. He also inherited the numerous schemes designed and redesigned by some of the greatest architectural and engineering minds of the 16th century. There were certain common elements in these schemes. They all called for a dome to equal that engineered by Brunelleschi a century earlier and which has since dominated the skyline of Renaissance Florence, and they all called for a strongly symmetrical plan of either Greek Cross form, like the iconic St. Mark's Basilica in Venice, or of a Latin Cross with the transepts of identical form to the chancel, as at Florence Cathedral.

Even though the work had progressed only a little in 40 years, Michelangelo did not simply dismiss the ideas of the previous architects. He drew on them in developing a grand vision. Above all, Michelangelo recognized the essential quality of Bramante's original design. He reverted to the Greek Cross and, as Helen Gardner expresses it: "Without destroying the centralising features of Bramante's plan, Michelangelo, with a few strokes of the pen converted its snowflake complexity into massive, cohesive unity."

As it stands today, St. Peter's has been extended with a nave by Carlo Maderno. It is the chancel end (the ecclesiastical "Eastern end") with its huge centrally placed dome that is the work of Michelangelo. Because of its location within the Vatican State and because the projection of the nave screens the dome from sight when the building is approached from the square in front of it, the work of Michelangelo is best appreciated from a distance. What becomes apparent is that the architect has greatly reduced the clearly defined geometric forms of Bramante's plan of a square with square projections, and also of Raphael's plan of a square with semi-circular projections. Michelangelo has blurred the definition of the geometry by making the external masonry of massive proportions and filling in every corner with a small vestry or stairwell. The effect created is of a continuous wall-surface that is folded or fractured at different angles, but lacks the right-angles which usually define change of direction at the corners of a building. This exterior is surrounded by a giant order of Corinthian pilasters all set at slightly different angles to each other, in keeping with the ever-changing angles of the wall's surface. Above them the huge cornice ripples in a continuous band, giving the appearance of keeping the whole building in a state of compression.

Dome – successive designs and final solution

The dome of St. Peter's rises to a total height of 136.57 m from the floor of the basilica to the top of the external cross. It is the tallest dome in the world. Its internal diameter is 41.47 m, slightly smaller than two of the three other huge domes that preceded it, those of the Pantheon of Ancient Rome, 43.3 m, and Florence Cathedral of the Early Renaissance, 44 m. It has a greater diameter by approximately 30 ft than Constantinople's Hagia Sophia church, completed in 537. It was to the domes of the Pantheon and Florence duomo that the architects of St. Peter's looked for solutions as to how to go about building what was conceived, from the outset, as the greatest dome of Christendom.

Bramante and Sangallo, 1506 and 1513

The dome of the Pantheon stands on a circular wall with no entrances or windows except a single door. The whole building is as high as it is wide. Its dome is constructed in a single shell of concrete, made light by the inclusion of a large amount of the volcanic stones tuff and pumice. The inner surface of the dome is deeply coffered which has the effect of creating both vertical and horizontal ribs, while lightening the overall load. At the summit is an ocular opening 8 m across which provides light to the interior.

Sangallo's plan (1513), of which a large wooden model still exists, looks to both these predecessors. He realised the value of both the coffering at the Pantheon and the outer stone ribs at Florence Cathedral. He strengthened and extended the peristyle of Bramante into a series of arched and ordered openings around the base, with a second such arcade set back in a tier above the first. In his hands, the rather delicate form of the lantern, based closely on that in Florence, became a massive structure, surrounded by a projecting base, a peristyle and surmounted by a spire of conic form.

The change of plan

On the first day of Lent, 18 February 1606, under Pope Paul V, the dismantling of the remaining parts of the Constantinian basilica began. The marble cross set at the top of the pediment by Pope Sylvester and the Emperor Constantine was lowered to the ground. The timbers were salvaged for the roof of the Borghese Palace and two rare black marble columns, the largest of their kind, were carefully stored and later used in the narthex. The tombs of various popes were opened, treasures removed and plans made for reinterment in the new basilica. To hold the sacramental Host, he designed a miniature version in gilt bronze of Bramante's Tempietto, the little chapel that marks the place of the death of St. Peter. On either side is an angel, one gazing in rapt adoration and the other looking towards the viewer in welcome. Bernini died in 1680 in his 82nd year.

  • Geographic orientation = chancel west, nave east
  • Capacity = 60,000 +
  • Total length = 730 ft
  • Total width = 500 ft
  • Interior length incl. vestibule = 693.8 ft,<ref name="cathency"/> more than 1/8 mile.
  • Length of the transepts in interior = 451 ft<ref name="cathency"/>
  • Width of nave = 90.2 ft<ref name="cathency"/>
  • Width at the tribune = 78.7 ft<ref name="cathency"/>
  • Internal width at transepts = 451 ft<ref name="cathency"/>
  • Internal height of nave = 151.5 ft high<ref name="cathency"/>
  • Total area = 227070 ft2, more than 5 acre.
  • Internal area = 163182.2 ft2<ref name="cathency"/>

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  • Height from pavement to top of cross = 452 ft
  • Façade = 167 ft high by 375 ft wide
  • Vestibule = 232.9 ft feet wide, 44.2 ft deep, and 91.8 ft high<ref name="cathency"/>
  • The internal columns and pilasters = 92 ft tall
  • The circumference of the central piers = 240 ft
  • Outer diameter of dome = 137.7 ft<ref name="cathency"/>
  • The drum of the dome = 630 ft in circumference and 65.6 ft high, rising to 240 ft from the ground
  • The lantern = 63 ft high
  • The ball and cross = 8 and, respectively
  • St. Peter's Square = 1115 ft long, 787.3 ft wide<ref name="cathency"/>
  • Each arm of the colonnade = 306 ft long, and 64 ft high
  • The colonnades have 248 columns, 88 pilasters, and 140 statues<ref name="cathency"/>
  • Obelisk = 83.6 ft. Total height with base and cross, 132 ft.
  • Weight of obelisk = 360.2 short ton<ref name="cathency"/>




  • First published 1896, current edition 2001.
  • . The 1905 edition is available from the Internet Archive.

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