The Making of St. Peter’s Basilica: History, Controversies and Genius at Work

by Francesco Bonavita, Ph. D. 

 Vatikan Panorama in Rom, Italien

A view of St. Peter’s in front of an Egyptian obelisk, which was brought to Rome some 2500 years ago.

Part I


For many centuries, on grounds of religious considerations, the Christian tradition at St. Peter’s Basilica was reluctant to initiate any sort of excavation beneath the base of the church. Thus, since its origin, there sat an incredible wealth of archeological, historical and religious accounts. Despite a long series of Popes who led the Church since the Fourth century AD, and a whole slew of visitors who came from all over the world, as well as artists, architects, sculptors, artisans and countless workers who helped to shape the Basilica into one of the world’s most admired holy grounds, the hidden treasures of the underground Vatican have been precluded from the public, as they have come to light only within the last few decades. Indeed, Pope Pius XII gave permission to begin archeological excavations in 1941 because when his predecessor, Pius XI, died in 1939, he let it be known that his greatest desire was to be buried as close as possible to St. Peter’s tomb. Much to their surprise, the archeologists came upon an impressive discovery: a Roman necropolis from the First and Second century CE, which was situated in the heart of Caligula’s and Nero’s arena.

Castore and Polluce Temple, Foro Romano, Rome

The Basilica was built on the grounds where there was a Roman arena.


It appears that the existing Basilica was built on the grounds known as ager Vaticanus (Vatican field), situated right where the arena was located. The grounds connected to the fortification, which today is commonly known as Castel Sant’Angelo. In the First century, Nero restructured Caligula’s arena. It was a huge circus, with an oval shape, used for performances and chariot races, as well as military training grounds. During the Great fire of Rome in 64 AD, Nero turned the area into a killing field, executing hundreds of Christians for their alleged role in the burning of Rome, which was presumably orchestrated by the Emperor himself. In time, the entire area became a necropolis. In the Fourth century, when Emperor Constantine converted to Christianity, the area was earmarked for the creation of St. Peter’s Basilica. This was a significant development in that all Christians were liberated and Christianity became the official religion of the Roman Empire.

The Rise of the New Basilica under Constantine


What strikes the visitor upon seeing the necropolis beneath the Basilica is its decorative richness. Its walls are endowed with niches, arches and paintings; its floors are adorned with mosaics, sarcophagi, and cinerary urns, made out of marble or alabaster. St. Peter is buried here at approximately fourteen feet below the main altar. From the very onset, this became an area of worship with hundreds of worshippers making a pilgrimage from all over the world. It is believed that a modest tomb was built originally at around 160 CE and it resembled a little chimney.

Lights of the Vatican

The tomb of St. Peter bears the Greek inscription “Petrus eni,” Peter is here.


In 312 CE, before battling Maxentius over the control for the Empire, Emperor Constantine had a vision whereby the battle is seen as a divine intervention in the course of history. As a result of this religious experience, Constantine grants all Christians Roman citizenship, unconditional freedom and orders for the church of St. Peter’s to be built on the Vatican field. This was a monumental project in that it required leveling the grounds, which was compounded by having to build over the existing necropolis. The construction, which took many years, when completed, became one of the most beautiful religious site of its kind and it housed the holy seat of Christianity for nearly twelve hundred years, before it could be demolished, in the Sixteenth century, in order to make room for the current Basilica.

Arch of Constantine in Rome, ItalyThe Arch of Constantine, in honor of the Roman Emperor who changed the course of history when he converted to Christianity.

This imposing structure had a series of steps, leading to the main façade, which had three main doors and a bell tower, topped by a golden rooster. Upon entering the site, visitors would make their way onto a squared atrium, called the Paradise Garden, at the center of which there was a huge bronze fountain in the shape of a pine cone that can still be seen today in the Vatican Gardens. This was a symbolic fountain in that it spouted water as a source of spiritual cleansing for the visitors. Although the Basilica is no longer in place, we have a plethora of materials that have come down to us through the ages, by means of written testimony and pictorial accounts, the most notable of which is the detailed map drawn by the cleric Tiberio Alfarano who wanted to make sure that subsequent generations had a good view of what the church looked like.


An illustration by Tiberio Alfarano in 1567 illustrates how the original Basilica appeared.

Part II

Early History of the Basilica

After the church was built and Emperor Constantine had chosen Constantinople, modern-day Istanbul, as the new location for the Byzantine Empire, Rome experienced a significant decline and ongoing pillaging at the hands of Goths and other Germanic tribes that invaded Italy on a periodic basis. Ironically, the Church itself suffered relative few damages as compared to cities and towns across Italy. The reason for this is that the Church was seen as inclusive and representative of all ethnic groups. In addition, many of the Goths gradually converted to Christianity. In contrast, the Saracens who invaded Rome in 843 CE were hardly benevolent, as they sacked the Basilica for all its gold and silver they could find. Fortunately, the golden rooster that topped the bell tower was not taken. This splendid sculpture can be seen today at the Vatican Museums, as a testament of what fine decorative pieces the old church may have contained. The rooster, of course, is a very symbolic icon in that it is intimately associated with St. Peter himself, because according to the New Testament he betrayed Christ three times, each time the rooster crowed.

Throughout the years, each pope worked assiduously to embellish and transform the Basilica into a veritable shrine so much so that by the beginning of the Eighth century, thousands of pilgrims would come to Rome from all over Europe on a weekly basis. The power of the Vatican grew by leaps and bounds, up until the Christmas of 799 CE when, Emperor Charlemagne was crowned by the pope, as Emperor of the Holy Roman Empire. This must have been a memorable ceremony not only on account of the numerous visitors but also because the church was illuminated with thousands of candles. Raphael has given us a vivid account of this festive and historical occasion, which can still be seen in the so-called Constantine Hall.

The ascendance of the church was not always void of difficult moments. In 1300, the leadership of the Church suffered a major setback when Pope Boniface VIII decided unilaterally to institute a periodic Jubilee event, which would take place every twenty-five years. The Pope who arguably must have been one of the worse popes in the history of the Church, managed to alienate a considerable segment of European thinkers. They saw the Pope’s Jubilee as a ploy to sell indulgences and as a means to silence any papal opposition. Among the many intellectuals, Dante was particularly taken aback so much so that Pope Boniface VIII ends up in his Inferno, as one of the most corrupted popes that Christianity has ever experienced. So, too, many prelates were infuriated and as a result the Church reached the famous Schism, which saw the papacy moved to Avignon, France, for nearly a century.

As one can imagine, the Fourteenth century witnessed a regression with respect to the stride forward marked by the Church, thus far. In the absence of a vibrant papacy, the Basilica underwent a period of decadence. With the advent of the return of the papal seat to Rome, leaders began thinking seriously about a restoration project. This initiative coincides with a new way of thinking about how men ought to play their role on earth. This was the beginning of the Renaissance, which at the onset of the Fifteenth century was spreading like wildfire. The leaders of the Church began to seriously consider replacing the Basilica altogether in order to express a new world order. This was no easy project to undertake, as St. Peter’s Basilica was also seen as a holy ground.

To complicate matters, the old Basilica had a holy shrine around the tomb of St. Peter, which consisted of twelve pillars that originated from the Middle East during the Third century. It is believed that they came from the Temple of Solomon in Jerusalem and that Jesus used one of its pillars to lean against it while praying. In addition to being one of the most beautiful churches of all times, there were many areas of the old Basilica that were intimately connected to history, which made its demolishing project a very complicated undertaking. The red marble floor piece, for example, with its circular design marked the exact area whereby the Emperor Charlemagne, supposedly knelt upon receiving the coronation as a Holy Emperor. So, too, the majestic holy door, which was entirely redone by Filarete in 1430, after the original one had been damaged by the Saracens. Filarete was a Florentine Renaissance artist whose bronze door depicts scenes from the New Testament and, most notably, St. Peter’s and St. Paul’s crucifixion. Similarly, the famous mosaic of the Navicella (The Little Ship), created by Giotto around 1305, which occupied a large part of the wall, at the entrance of the old Basilica, was a work of art that made it difficult for anyone to part with. These, together with a multitude of treasures, constituted a substantial obstacle for the restoration project to move forward.

Finally, in 1450, Leon Battista Alberti, the famous Florentine humanist, architect, inventor and a scholar of the Renaissance, declared that the structure of the old Basilica was in danger of collapsing, thus recommending a new church, altogether. In the eyes of the humanists, the old Church was seen as a medieval structure and, as such, it was looked upon as an anomaly. The Church, on the other hand, interpreted these recommendations as sacrilegious, which needed to be strongly resisted. Thus, the project went from one hand to another, until Pope Julius II appeared on the scene.

Part III


The Building of the Second Basilica

The Moses in St. Peter Vincoli church

Michelangelo’s Tomb of Pope Julius II in St. Peter Vincoli Church. Arrogant, autonomous and a strong leader, Pope Julius II was determined to move the Basilica project ahead.


Julius II was an ambitious pope who came to be called “the warrior Pope” and felt he had infinite divine power, religious, political and otherwise. He was obsessed by the idea of making St. Peter’s Basilica the most magnificent sight in the world and he wished to be remembered as one of the greatest popes of all times. To this end, he needed to finance the project by increasing indulgences, even if it meant offending members of the curia outside Rome. Julius II was initially interested in creating his own tomb, as he wished to be remembered by posterity, in much the same way one can recall the feats of Julius Caesar. Ironically, this pope was motivated to serve his own agenda by having his own colossal tomb, before restructuring the Basilica. For this purpose, he called upon Michelangelo to design the project. Although the Florentine artist was only twenty-three when he was recommended for this monumental task, his reputation had already been established, first with the Pietà, David and then with the Tomb of the Medici family, in Florence. Much to his chagrin, Julius II soon realized that the old Basilica would not be able to accommodate for his lofty project. This is when he decided to go ahead for the construction a new church. He commissioned the architect Antonio da Sangallo who worked on a wooden model for eight years, before presenting it to the pope. Sangallo’s design, which can still be seen today at the Vatican Museums, is remarkably intriguing, as it measures approximately 16’x22’ in dimension.

Church of the Madonna di San Biagio in the vicinity of Montepulciano. Italy

The architecture of Sangallo in Montepulciano who was working on a wooden model of the Basilica, which was never brought to bear because the Florentine architect died prematurely.


Although Sangallo’s project envisioned a cupola, the two bell towers flanking the façade of the Basilica appeared to have detracted and obscured the beauty of dome. This may have been the reason why Julius II opted for Donato Bramante’s design. The work of Bramante envisioned a revolutionary concept based on a Greek rather than a Latin cross, as a base. The dome would rest on a square and the Basilica would not have five naves, as had been suggested by Sangallo. Bramante was an established architect in his own right. His famous work at Santa Maria delle Grazie, in Milan, which houses Leonardo da Vinci’s Last Supper, exhibited a remarkable dome in a perfect circular design resting on a cube. This geometrical effect gives the viewer an optical illusion of a cupola resting on a cubic structure. Pope Julius gave Bramante full approval for this project, but as destiny would have it, the famous architect and painter died in 1514, before he could even get started.

santa maria delle grazie, milano

Santa Maria delle Grazie in Milan by Bramante whose model of the Dome failed to generate sufficient sunlight.

The work on the Basilica was proceeding slowly, because in addition to Julius’ death, which occurred at around the same time of Bramante, the Sack of Rome in 1527, brought about by the French troops, which created instability for the Church and the lack of funding to continue the project, all of which did not bode well with the Vatican whose ambition was to bring the work to a speedy conclusion.

Italia,Toscana,Firenze,David di Michelangiolo

A copy of Michelangelo’s David in Florence. The Florentine artist  had a tempestuous relationship with Pope Julius II.

When the work was resumed, Michelangelo was summoned by Pope Paul III in an effort to put a finishing touch on the Basilica. In 1546, Michelangelo was 71 years old and had no plans to get involved, as he had already accomplished so much. The Pope insisted and even promised to remunerate him with a hefty sum of money, but Michelangelo refused any monetary compensation and decided instead to take on the project for personal spiritual reasons. Michelangelo’s project was much more economically sound than the one originally conceived by Sangallo. He worked at a frenetic pace, utilizing as many as ten thousand artisans. He refined Bramante’s plans and in the course of two years the dome was erected and the basic structure of the Basilica was completed. For the creation of the dome, Michelangelo was inspired by the Pantheon in Rome and the dome of Brunelleschi in Florence. The structure itself is made out of wood. Iron bands all around the dome were used to provide support and bricks covered the spaces. The artist himself, to ensure perfect results and to attain the desired effects, inspected the bricks, one by one, personally.

Dome of St. Peter's Basilica in Vatican.

Michelangelo’s Dome set a new bar for architecture, which would be emulated throughout the world, most notably, the U.S. Congress, Saint Paul’s Cathedral in London and Les Invalides in Paris.


The Dome from the interior measures approximately 140 ft. in diameter, which is slightly smaller than Brunelleschi’s famous cupola in Florence and the Pantheon of Rome. What makes Michelangelo’s dome unique is that it provides ample light. It’s as if the Glory of God filters through the cupola on any given day. Michelangelo’s work set a new bar and his work becomes a model for Saint Paul’s Cathedral in London, Les Invalides in Paris and the United States Congress in Washington, DC. Although the lantern, which tops the cupola, was left unfinished, Michelangelo left behind specific instructions for subsequent architects to compete the work.

Upon completion of the Basilica, Michelangelo felt very strongly about leaving the house of worship bare. He voiced his opposition to any attempts to embellish the divine shrine because it would be in line with the simplicity of Christ himself. The artist’s wishes were not heeded, as every succeeding pope was deeply committed to the notion that St. Peter’s Basilica had to reflect splendor and grandiosity. Thus, a young artist emerged on the scene, just a few years after Michelangelo passed.

Part IV


A Sublime Experience

Piazza San Pietro, Colonnato, Roma

This is the Colonnato of Gian Lorenzo Bernini who was a painter, sculptor, architect, playwright and a universal man who single-handedly left his Baroque vision throughout Rome.


Gian Lorenzo Bernini was hardly twenty years old when his reputation as one of the greatest artists in Rome came to the fore. He was a universal man and had already created a whole series of statues for the Borghese Gallery. He was not simply a sculptor rather he excelled in every imaginable artistic form. He was a painter, a playwright, a poet, an interior decorator, an architect and an inventor. In short, he was a genius whose Baroque style left an indelible imprint on the city of Rome.

A prolific artist endowed with an uncanny ability to assemble hundreds of craftsmen, Gian Lorenzo Bernini became the uncontested coordinator of St. Peter’s Basilica. For six decades, he worked for many popes, most notably Urban VIII and Alexander VII for whom tombs he created in their memory.

The first major significant work by Bernini is the so-called Baldacchino, which is a highly decorative canopy that embellishes the main altar of the Basilica. It is a majestic structure, measuring 66 ft. in height and it stands perpendicularly above St. Peter’s tomb. It stands monumentally on four columns, which are decorated in bronze and they combine sculpture and architecture, an important development for Baroque art. The canopy is resting on the four helical columns, each of which stands on a marble pedestal. On the canopy stand four large size angels supporting a sphere, which represents the world redeemed by Christianity. The columns are shaped in a helical form that recall those of the original Temple of Solomon where, supposedly, Christ is said to have worshipped there.

St Peter's Basilica - baldachin

The Baldacchino by Gian Lorenzo Bernini is an imposing altar situated directly above St. Peter’s tomb.

Upon completion of the decorative aspects of the Basilica, Bernini undertook to create the largest Baroque square in the world in an effort to give the Basilica an eminent preamble, before entering the holy grounds. The effects are astonishing, as the Colonnato with 140 statues on top of the Doric style columns and adorned with Travertine marble, symbolically represent the arms of the Church, accepting every human being. The square is embellished with two symmetric fountains and at the center of which there lies the Egyptian Obelisk that was brought to Rome by Caesar Augustus. The obelisk represents the continuity of civilization in that the cultural chain between the east and the west is unbroken. On the square itself, between the Obelisk and the fountains there are white discs, whereby one can stand on it and see only one row of columns, rather than four, creating an optical illusion.

Roma - Citta' del Vaticano: Basilica di san Pietro

The Colonnato of Bernini decorates the largest Baroque square in the world.

The history of the two Basilicas is replete with so many accounts, all of which provide a narrative of amazing developments. With respect to the first Basilica, the history of the Catholic Church is unfolded within this context. As the Roman Empire was coming to a close due to the consistent invasions by the Huns, the Church provided a point of reference in the midst of social turmoil. It quickly established itself as a spiritual and political power throughout Europe. The Basilica was at the center of the dialog. The coronation of Charlemagne in 799 CE at St. Peter’s establishes the Church with a clear spiritual mandate in that no political leadership can flourish without the sanction of the Vatican. The building of the second Basilica, on the other hand, created a spiritual crisis within the Catholic Church that ultimately led to the Reformation. In their fervent desire to erect the greatest house of worship the Vatican coffers needed all the financial resources they could access. In doing so, the popes had to come up with creative schemes even if it meant risking a bitter reaction from the Northern curia, most notably Martin Luther who ended up heading the Protestant movement. In the final analysis, though, the Catholic Church survived its most severe challenge by virtue of great papal leadership, such as Nicholas V and Julius II. The former Pope Nicholas V, a Renaissance man, was truly a magical moment for the Catholic Church. He was a scholar and a humanist. He was well read in Latin, Green and Italian. He resolved the Schism that had been threatening the unity of the Church and invited nobles to the papal court. He resuscitated the concept of Jubilee or the Holy Year in 1450. Millions of people descended on Rome from all over Europe, on foot, on horseback, on ox cart, and by ship. These pilgrims braved the long voyage in order to receive a pardon for their sins and in return they helped fill the Vatican coffers, needed for the construction of the new Basilica. In short, he managed to establish St. Peter’s Basilica as the uncontested seat of Christianity. Julius II, on the other hand, as controversial as he was, succeeded in moving forth the notion that the artistic genius was needed to convey the Christian message to the people. Bringing Michelangelo to the Vatican and ultimately endorsing the universal genius of Gian Lorenzo Bernini accentuated the artistic expression to another realm, which was embraced by people from all walks of life. St. Peter’s Basilica is not just a house of worship it is a museum and a spiritual testament of mankind. It represents the power of creativity and of mankind in all its dimensions whereby one can experience the sublime. One cannot predict if the second Basilica can last twelve hundred years as did the first, but what is certain is that the creative geniuses of Michelangelo and Bernini will outlive the test of temporal time and it will forever engage the minds and imagination of future generations.


Angela, Alberto. San Pietro: Segreti e meraviglie in un racconto lungo duemila anni. Rizzoli: Milano, 2015.

Carmen C. Bambach and Claire Barry. Michelangelo: Divine Draftsman and Designer. The MET: Yale University Pr., 2017.

Franco Mormando. Bernini: His Life and his Rome. Chicago: University of Chicago Pr., 2015.


3 thoughts on “The Making of St. Peter’s Basilica: History, Controversies and Genius at Work”

  1. Your article is insightful and detailed. It’s like taking an architecture course online. The language is clear, straight-forward, and eloquent! Thank you for posting.

    Liked by 2 people

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