Saint Peter’s Basilica is an immense building which is generally ranked as the largest church in the world, with an internal length of 186.36 metres and an internal width of 91 metres, amounting to an internal floor space of 15,160 square metres.
The construction of the basilica as we see it today began in 1506, when the old basilica was torn down, and it was finished in 1614, although it was not consecrated until 18 November, 1626. The church was designed by several leading architects of the Renaissance and Baroque periods, including Bramante, Michelangelo and Carlo Maderno.
The apostle Peter died a martyr in the first century AD, having refused to flee Rome during the persecution of Christians ordered by the Emperor Nero, who used them as easy scapegoats for the fire of Rome in 64 AD, which many people believed he himself had started. According to legend St. Peter was crucified upside-down, either on the slopes of the Janiculum Hill (about a kilometre south-east of the present basilica), or inside the Circus of Caligula, a racetrack for chariot racing, built by the mad emperor Caligula on the Ager Vaticanus, an area of privately owned land to the north-west of the city.
St. Peter was then buried next to the Via Cornelia, a Roma road that ran alongside the circus. He is considered to be the first Pope, and the small shrine that was built to mark his resting place was therefore the location of choice for what was destined to be the most important sanctuary and spiritual centre of the Catholic Church.
The First Basilica
In 319 AD, on the slopes of the Vatican Hill north of the Transtiberim district on the west side of the River Tiber (now known as Trastevere), the Emperor Constantine decided to build a large Basilica dedicated to St. Peter. It was consecrated in 326 AD although construction work probably continued until around 340 AD. The entrance to the basilica was preceded by a large colonnaded square and the building itself, over 103 metres (340 ft) long, had a wide nave with two side aisles, culminating in a transept and a curved apse at the western end. In fact, like all the earliest Christian churches, the entrance was to the east, although five centuries later this orientation was reversed, to follow the Byzantine convention. The basilica was built over a small shrine believed to mark the burial place of St. Peter. This holy site was damaged and desecrated during a Saracen raid in 846 AD, but the massive building with its 120 altars remained standing until the papacy of Pope Julius II (1503 – 1513). However by the 15th century, when the popes returned from Avignon, it was falling into ruin (in fact the Renaissance architect Leon Battista Alberti considered that it could collapse at any moment). Pope Julius II therefore entrusted the Milanese architect Donato Bramante with the project for a new St. Peter’s Basilica and the old church was progressively demolished, starting from 1506, when the first foundation stone of the new building was laid. Pope Julius II’s foresight and ambition led to the construction of the most impressive and famous church in the world, which rose gradually over the next 120 years, with several changes of plan. Many great artists and architects such as Raphael, Baldassare Peruzzi, Antonio da Sangallo the Younger, Michelangelo, Carlo Maderno and Gian Lorenzo Bernini would work on the building. However, the new basilica also led to the schism in western Christianity known as the Reformation, because Pope Julius decided to raise the vast sums of money needed to build his new church by the sale of indulgences, a practice that Martin Luther abhorred. His so called “95 Theses”, upon which Protestantism was founded, explicitly refuted the power and efficacy of indulgences.
The New Basilica
Bramante proposed a highly complex and almost labyrinthine structure based on the centralized and symmetrical plan of a mausoleum. It was to be a massive square building into which a Greek Cross (with four arms of equal lengths) would fit, with an immense dome rising in the centre and four subsidiary domes in the corners of the square.
The dome was intended to rival the one built by Brunelleschi in Florence a century earlier. But Pope Julius died in 1513 when the pilasters to support the dome had hardly been begun. The ageing Bramante outlived him by only a year and was succeeded by Giuliano da Sangallo, Fra Giocondo and then Raphael as “Capomaestro”, or superintendent of the building works. He proposed a radical change to the plan involving a nave five bays long, with a series of chapels on either side and a colonnaded portico at the entrance. The length of the chancel and transepts was to be reduced, and their semi-circular apses would be provided with an ambulatory. But in 1520 Raphael died, suddenly and unexpectedly, on his 37th birthday, and his replacement Baldassare Peruzzi reverted to the Greek Cross idea. However this plan was put on hold following the sack of Rome in 1527 and Peruzzi’s death at the age of 54.
Things seemed destined to change again thanks to the involvement of Antonio da Sangallo the Younger, who proposed adding a curious free-standing facade with two towers on either side, as well as ribs on the exterior of the dome, which would be supported a colonnaded drum and topped by a massive lantern. An enormous wooden model on a scale of 1:29 (width 602 cm x length 736 cm x height 468 cm) of this plan still survives. It took seven years to build and cost almost as much as the construction of a small church. But Sangallo contracted malaria and died in 1546 and Pope Paul III promptly gave Michelangelo the job of “Capomaestro”.
Michelangelo was seventy-one years old and was rather reluctant to take on such an enormous task (which he perhaps even felt might be jinxed, following the deaths of no less than six architects in the space of 32 years). He declared “I undertake this only for the love of God and in honour of the Apostle”. Michelangelo drew on several ideas in the previous plans but basically reverted to Bramante’s original Greek Cross design, simplifying the concept of a cross within a square and emphasising its essential qualities. The basilica now had a coherent sense of massive unity.
By the time of Michelangelo’s death in 1564 the imposing base or “drum” of the dome had been raised. The dome as we see it today, divided into sixteen sections by raised ribs, was finally completed in 1590 by Giacomo della Porta, who had been appointed by the energetic Pope Sixtus V in 1585. He slightly modified Michelangelo’s plans by raising the height of the dome by about seven meters, so that it would dominate the Roman skyline even more effectively. The lantern atop the dome was then completed by Domenico Fontana.
In 1607 Pope Paul V gave Carlo Maderno the task of extending the building by the addition of a nave, thus returning to the concept of Raphael’s Latin cross plan. The nave and the squat façade were completed in 1614, and the basilica was ready for use by Palm Sunday 1615. Nevertheless the church was not consecrated until the 18th of November 1626 by Pope Urban VIII, exactly 1300 years after the consecration of the first church.
Ever since then St. Peter’s Basilica has been the centre of Catholicism, visited every year by millions of pilgrims and tourists from all over the world (an estimated 5.9 million people visited the Vatican in 2014).
The building is truly gigantic and it can house a congregation of over 20,000 people. It has an external length of 211.50 metres (including the portico or narthex) and the exterior of the dome is 58.9 meters in diameter (internal diameter = 41.5 meters), reaching a height of 136.5 meters to the top of the cross upon the lantern. Upon entering the basilica, visitors are awestruck by its magnificence and the artistic masterpieces it contains, with many sculptural monuments and beautiful statues, some of them dating back to the original basilica built by Constantine.
One peculiarity of the artworks in St. Peter’s is the fact that, starting from the seventeenth century, the paintings which originally adorned the church were substituted by mosaic replicas. Unlike paintings, mosaics cannot easily be damaged or stolen, and they do not lose their bright colours, so in this way the artworks could endure over time. In the eighteenth century an opaque paste was developed that eliminated the normal reflections of mosaics and that could simulate the many shades of colour used in paintings, and minute details could also be reproduced thanks to the tiny pieces (known as tesserae) that these mosaics are made of. There are now over 10,000 square metres of mosaic in the Basilica, including those inside the dome. Seen from a distance they are almost identical to genuine paintings.
The most famous of all the sculptures and artworks inside St. Peter’s is undoubtedly the work by Michelangelo known as the Pietà, which shows Christ being mourned by the Virgin Mary after his death by crucifixion, and which is now kept in the first chapel on the right as one enters the basilica. It was commissioned on August 27th 1498 by a French Cardinal who wanted it as his funeral monument. At that time Michelangelo was only 23 years old and still relatively unknown outside Florence.
In fact, according to his biographer Giorgio Vasari, soon after the work was completed, Michelangelo overheard someone saying that it was the work of another sculptor. He therefore returned to the church at night and carved his signature MICHAEL⋅AGELUS⋅ BONAROTUS⋅ FLORENT⋅ FACIEBA (Michelangelo Buonarroti the Florentine made this) on the sash running across Mary’s chest. This is the only work which bears Michelangelo’s signature and Vasari says that he later regretted his youthful expression of pride and never signed any other of his works.
Vasari writes that “It is certainly a miracle that a formless block of stone could ever have been reduced to such perfection as nature is scarcely able to create in the flesh.” Thanks to the fame that Michelangelo gained by creating the Pietà he was invited to return to Florence where he sculpted the iconic monumental statue of David.
In this work Mary is represented by as a young woman, seated on a rock symbolizing Golgotha, the mountain outside Jerusalem where Jesus was crucified. The delicate almost child-like body of Jesus lies across her laps. Mary’s face seems far too young for the mother of a man who was traditionally 33 years old when he died, but Michelangelo probably wanted to express her inner spiritual purity and virginity, manifested externally in her youthful beauty. This theme of Northern European origin was unprecedented in Italian sculpture, but Michelangelo would return to it twice, over fifty years later, in the Bandini Pietà (or Deposition) and the Rondanini Pietà.
Sadly the Pietà was damaged by a religious fanatic, the Australian Laszlo Toth, who attacked it with a geologist’s hammer on May 21, 1972, while shouting “I am Jesus Christ! I have risen from the dead!” He struck the sculpture fifteen times, breaking off Mary’s arm at the elbow and much of her nose, and chipping one of her eyelids. Even more shocking is the fact that many onlookers picked up the broken pieces of marble that were lying on the floor and stole them.
The work had to be painstakingly reconstructed and restored using pieces cut from the back of the statue. Due to fears that a similar act of vandalism and theft might be repeated the work is now protected from the public by a bulletproof acrylic glass panel.
Of course there are many other important artworks in the basilica, such as the bronze canopy known as the Baldachin and the Chair of St. Peter, both by Gian Lorenzo Bernini, as well as the ancient bronze statue of St. Peter.
Immediately inside the central door a large round piece of the purple stone known as porphyry is embedded in the floor. According to legend it was on this stone, originally located near the main altar in the basilica of Constantine, that Charlemagne knelt on Christmas day in the year 800 during the ceremony of his coronation. This example would be followed by 21 other Holy Roman Emperors who were also crowned there.
The refined geometric design of the coloured marble floor was devised by Bernini for the 1650 jubilee, together with the rich stucco decorations of the nave. The niches in the four massive pillars that separate the nave from the aisles are occupied by marble statues of saints who founded religious orders. But the lower niche on the last pillar on the right is occupied by the life-sized bronze statue of St. Peter enthroned, holding the papal keys and with his right hand raised in the act of blessing.
The origins of this artwork are still disputed. It has been attributed to the 13th century sculptor Arnolfo di Cambio, although some scholars maintain that it dates back to the sixth century. On 29 June, the feast of St. Peter, the statue is clothed with papal finery including a tiara, a stole, a cope and a ring, so that it almost seems to have come to life. Over the centuries many pilgrims have reverently touched and kissed its projecting right foot, so that it has been worn completely smooth.
This tradition was sanctioned in the 19th century by Pope Pius IX, represented in a mosaic above the statue, who granted an indulgence to pilgrims who performed this act of homage. According to another tradition, St. Peters papacy of twenty-five years would never be exceeded, but Pope Pius IX reigned for thirty-one years. Perhaps the power he wielded for so long went to his head, because in 1870, during the First Vatican Council, he issued a document entitled “Pastor Aeternus” (The Eternal Shepherd) that established the doctrine of Papal infallibility. Though the “eternal shepherd” of the title refers to Jesus Christ, some people joked that it actually referred to Pius IX, whose pontificate seemed due to last forever!
Along the trabeation that runs between the arches of the central nave and the projecting cornice where the vault begins to rise two Latin texts are written in large black letters on a gold background. On the left (south) side it reads: “Ego rogavi pro te, o Petre, ut non deficiat fides tua: et tu aliquando converses confirma fraters tuos” (“I have prayed for you Peter, that your faith may never fail; and you in turn must strengthen your brothers” – Luke 22:32). On the right side are the words: “Quodcumque ligaveris super terram, erit ligatum etin coelis: et quodcumque solveris super terram, erit solutum et in coelis” (“I will entrust to you the keys of the kingdom of heaven. Whatever you declare bound on earth shall be bound in heaven; and whatever you declare loosed on earth shall be loosed in heaven” – Matthew 16:19).
The nave is spanned by a barrel vault which was richly decorated with coffering during the pontificate of Pope Pius VI in the late 18th-century. It reaches a height of 45.5 metres and a length of 98 metres.
Then the central space of the crossing opens up. Here we encounter the curving balustrade of the ‘Confessio’. This is a semicircular space below floor level accessed by a double staircase descending to the level of the grottoes, where the tomb of St Peter can be viewed through a glass panel. Inside the niche at the end of the Confessio, directly under the altar, is a bronze coffer containing bands of cloth embroidered with black crosses (known as “stoles” or “palliums”) woven from the wool of lambs blessed on the feast of St. Agnes (Jan 21). Perhaps deriving from the scarf of office of Roman Imperial officials this garment was originally worn by the Popes. It symbolizes the continuity of the Church’s authority over its flock.
The ‘Confessio’ is followed by the central altar surmounted by Bernini’s colossal bronze Baldachin, standing upon its intricate twisted columns. Above this rises the vast internal space of Michelangelo’s lofty dome.
The dome was designed by Michelangelo but when he died in 1564 it had only been built as far as its supporting drum. Michelangelo’s collaborator Giacomo Della Porta took charge of the construction, raising the outer masonry shell of the dome by about seven meters and completing it in 1590.
The lantern (a sort of pagoda above the dome allowing extra light to enter the building) is 17 meters high. The following inscription can be read around its circular base inside the dome: S. PETRI GLORIAE SIXTVS PP. V. A. M. D. XC. PONTIF. V. (“To the glory of St Peter Pope Sixtus V 1590, the fifth year of his pontificate”).
Around the base of the drum are words from the gospel of Matthew (16:18–19): TV ES PETRVS ET SVPER HANC PETRAM AEDIFICABO ECCLESIAM MEAM. TIBI DABO CLAVES REGNI CAELORVM (“You are Peter, and on this rock I will build my church. I will give you the keys of the kingdom of heaven”). Below this are the four pendentives which connect the circular drum to the supporting piers. upon them the four Evangelists and their symbols are shown in medallions with a diameter of 8.5 m: Matthew with his ox, Mark with his lion, Luke with his angel and John with his eagle.
The dome of St. Peter’s rises to a height of 136.5 metres (448 ft) measured from the floor of the basilica to the top of the external cross, making it the tallest dome in the world. Its internal diameter of 41.5 metres is however slightly less than that of the Pantheon (43.3 metres) and that of Florence Cathedral (44 metres). It has become the graceful and yet powerful symbol of the Rome of Christianity and the Popes, and due to its towering height it can be seen from almost anywhere in Rome.
This architectural masterpiece soon became a model for many other domes in the Western world. These include those of Saint Paul‘s in London (1675) with an internal diameter of 31 metres, Les Invalides in Paris (1680-1691) – internal diameter 26.2 metres, and the cast iron dome of the United States Capitol in Washington (1794-1817) – internal diameter 29 metres.
The baldachin (in Italian “baldacchino”) was the first of several works that Gian Lorenzo Bernini created in St. Peter’s. At 28.74 metres (94.3 ft) tall it is widely considered the largest bronze object in the world. Standing above the high altar it is a variation on the traditional form of the ciborium, a stone structure on columns that emphasises the place in a church where the Sacrament of the Eucharist is performed. Bernini combined this idea with that of the baldachin, a decorative brocade canopy often borne above relics and objects carried in religious processions or to protect the pope from the elements during public ceremonies. The twisted shape of these columns echoes that of the marble columns supposedly brought by the Emperor Constantine from the Temple of Jerusalem to build an altar screen in the old basilica. These columns are now embedded in niches that Bernini created in the piers below the dome.
The baldachin was commissioned by Pope Urban VIII of the Barberini family, and the work took eleven years, starting in 1623 and ending in 1634. It stands on a four marble plinths and its four helical bronze columns are decorated with bees, the heraldic emblem of the pope’s family, and laurel leaves, which possibly refer to his abilities as a poet. These huge columns support a canopy made of bronze, which marks the holy site below, where Saint Peter’s body was believed to lie. The canopy, with angels standing at each corner, is surmounted by four curved brackets leading up to a central platform that bears a gilded orb and cross. Also the leaves that enwrap the columns, the bees and the seraphs on the canopy, are picked out in gold leaf.
A fascinating detail can be seen on the eight massive marble plinths, each of which is decorated with the Barberini coat of arms on a shield, and the papal tiara with crossed keys. At the top of each shield is a woman’s portrait head with long flowing hair. This is said to represent Urban’s beloved niece Giulia during the painful process of childbirth, culminating in a smiling newborn baby like a winged cherub. Also the convex shields suggest the swelling forms of a pregnant female body.
The Throne of St. Peter
The baldachin is a sculptural object standing in the vast central space of the building. It thus creates a visual link between the tiny people at floor level in the crossing and the dome above it, suggesting the immensity of the heavens. It also leads the eye to the Cathedra Petri, or “throne of St. Peter” (also designed by Bernini) in the apse at the back of the church, which can be seen framed between the columns of the baldachin. This is a massive sculpted casing in gilt bronze for a wooden chair with ivory decorations, which was given by the Holy Roman Emperor Charles the Bald to Pope John VIII in 875. It is supposed to have been used by the apostle in person in his role as the first pontiff, but scientific examination has revealed that no part of it was made earlier than the sixth century.
Bernini’s cathedra (made between 1657 and 1666, some 30 years after the baldachin) is supported by massive bronze figures of four prominent Doctors of the Church, the saints Ambrose, Augustine of Hippo, John Chrysostom and Athanasius. They hold up the sacred relic so that it seems to hover behind the altar in the apse of the basilica. The Corinthian columns and pilasters on the wall behind it are enveloped by an explosion of golden clouds and sculpted sunbeams (here again Bernini is sculpting the “unsculptable”), and a central stained glass window contains an image of the holy spirit in the form of a dove, surrounded by a host of angels and cherubs. Like Bernini’s Ecstasy of Saint Theresa, here we witness his quintessentially Baroque fusion of the arts of sculpture and architecture, combined with dramatic and theatrical light effects.
The Piers in the Crossing
Four massive masonry piers support Michelangelo’s dome in the central space of the church. While he was building the baldachin Bernini had them hollowed out to create niches, with staircases inside them leading up to balconies. Many people thought that this might weaken the dome, perhaps even causing it to fall, but their fears proved unfounded. (This was sadly not the case for the bell towers that Pope Urban VIII unwisely asked Bernini to raise on either side of the facade of St. Peter’s, which had to be demolished when they caused cracks to appear).
On the balconies of the piers Bernini used the eight ancient twisted columns that had formed an altar screen in the original basilica, which visually echo the nearby baldachin. Here four precious relics of the basilica were displayed: the spear of Longinus, the centurion who supposedly wounded Christ while he was on the cross, the veil of Veronica, with a miraculous image of Christ’s face, a fragment of the True Cross brought from Jerusalem by the Emperor Constantine’s mother, Helena, and a relic of St. Andrew’s head. Each of the niches is occupied by a huge statue of the saint associated with these objects, but only the Saint Longinus was sculpted by Bernini, being completed in 1638. Instead Saint Helena holding the true cross and the holy nails is by Andrea Bolgi, Saint Andrew with his cross is by Francois Duquesnoy and Saint Veronica holding the veil is by Francesco Mochi.
The Swiss-Italian architect Carlo Maderno designed the façade of St. Peter’s, which was completed in 1614. It is 114.7 meters wide and 47.3 meters high (376 x 155 feet), and so its area is greater than that of an American football field (360 x 160 feet). Clusters of gigantic rounded columns and flat pilasters stand against the front of the building, unlike the free-standing columns of a shallow portico, as originally planned by Michelangelo. These support a grandiose cornice with a central tympanum, which in its turn is crowned by a balustrade made of a lighter-coloured travertine stone, with massive square windows and surmounted by thirteen statues.
The inscription on the cornice tells us when the façade was completed and under which pope. It reads: IN HONOREM PRINCIPIS APOST PAVLVS V BVRGHESIVS ROMANVS PONT MAX AN MDCXII PONT VII (In honour of the Prince of Apostles, Paul V Borghese, a Roman, Supreme Pontiff, in the year 1612, the seventh of his pontificate).
The window in the very centre of the façade above the entrance is called the “Loggia delle Benedizioni” (Loggia of Blessings). This is where the pope, following the announcement of a new Pontiff with the words “Habemus Papum” appears to give his “Urbi et Orbi” blessing to the city and to the world, as well as on Christmas Day and at Easter. The bas-relief under the balcony represents Christ giving the keys to St. Peter.
Perhaps Maderno’s plans were rushed, due to a desire to complete the building quickly, and in many ways the façade is the least satisfactory part of St. Peter’s church. In fact it seems excessively broad for its height, and the upper storey seems to be tacked onto the cornice and its pediment. The sense of immoderate breadth might have been extenuated if the initial plan to have bell towers on either side had been carried out, but when Bernini attempted to raise these towers they had to be demolished, as the existing foundations proved insufficient to bear the weight. One unfortunate effect of the lengthened nave and the massive façade of St. Peter’s is to block the view of the dome, which can only be properly seen and admired from a distance.
St. Peter’s Square
The square as we see it today was laid out by Gian Lorenzo Bernini in 1656-1667 under the direction of Pope Alexander VII, and it represents his most famous and most extensive intervention of urban planning and monumental architecture. Before this there was simply an oblong space lined by buildings. It was already occupied by the Egyptian obelisk, and the fountain to the north of the obelisk. Bernini divided this space into two parts.
The first is a vast ellipse 203 meters wide (245 meters if one includes the colonnade), designed to allow the greatest possible number of people to be present while the Pope gives his blessing, either from the “Loggia of Blessings” in the middle of the façade of the church or from a window in the Vatican Palace to the south. This space bounded by an immense colonnade which symbolizes the protective power and all-inclusive embrace of the church. The second space is a trapezium with its longest side corresponding to the façade of the basilica. By compressing the sides of the façade in this way, with the use of low constructions on either side, Bernini managed to give it a less squat and more imposing appearance, while also turning its excessive number of columns into a virtue, as they seem to multiply and expand into the colonnade when seen from a distance, so that the latter becomes its natural extension.
Several of Bernini’s assistants sculpted the coats of arms of Pope Alexander VII and the 140 statues of saints that stand on the architrave above the colonnade, each one corresponding to the position of a column. The colonnade is four columns deep and two special cobblestones near the fountains inside the square mark the position from which they each appear to be a single column due to a particular perspective effect. In 1675 Bernini installed a second fountain to the south in order to mirror the one created by Carlo Maderno in 1613. The obelisk was transported to Rome from Egypt in 37 AD to adorn the circus of Caligula, where it acted as a turning post for chariot races. The mad Emperor was so fond of this sport that he had his favourite racehorse, Incitatus, declared a senator. In 1586 the obelisk was moved from its position on the north side of the basilica and re-erected at the current site by the architect Domenico Fontana.