Dalla Chiesa di S. Pietro ha il principio questa mia fatica, cioŔ dalla maggior fabrica, che tutti i secoli habbino ammirata, ....
per accrescere la quale sono pi¨ volte restati esausti i tesori dell'Impero Christiano. (I begin my work with S. Pietro, the greatest enterprise ever
undertaken and the most admired one, .... for the embellishment of which more than once the finances of Christianity were exhausted).
Filippo Titi opens with these words his 1674 summary of the works of art in the churches of Rome. He points out the three main features of the church: its magnitude, its artistical value and its cost.
S. Pietro should more correctly be called S. Pietro Nuovo, because it replaced S. Pietro Vecchio, the large basilica of the IVth century which stood on the same site. It had five naves and it was the largest church in Rome, but in the XVth century the popes felt the need to enlarge and redesign it. Pope Eugenius IV (1431-1447) spent most of his pontificate in Florence and he attended there to the solemn ceremonies
for the completion of the dome of the Cathedral. He was impressed by both the size and the beauty of the Cupola del Brunelleschi, the dome designed by Filippo Brunelleschi. The Cathedral of Florence (S. Maria del Fiore) was by far larger than
S. Pietro Vecchio, its exterior was richly decorated with marble and the modern and daring design of its dome called for admiration.
The successor of Eugenius IV, Pope Nicholas V (1447-1455) was the first to develop a plan for modernizing S. Pietro Vecchio by enlarging its apse with the objective of making more evocative the ceremonies of the Holy Year 1450. Pilgrims were one of the main resources of Rome and the Church; they came moved by religious fervour, but they were also attracted by its large basilicas (and by other worldly pleasures).
The majority of them came to Rome through Florence and so they were in a position to compare the old and falling apart S. Pietro Vecchio with the new Cathedral of Florence.
Pope Julius II (1503-1513) took the decision to replace S. Pietro Vecchio with a totally new basilica and he appointed a body (the still existing Fabbrica di S. Pietro) in charge of the task. On April 18, 1506 the first stone of the new basilica was laid down.
The dimensions and the decoration of the new building were to be unsurpassable; the cost was too. The Reformation and the related religious wars, the Sack of Rome in 1527, the economic decline of Italy in the first half of the XVIth were events which slowed down the erection of S. Pietro Nuovo. The first part to be completed was Cappella Gregoriana named after Pope Gregory XIII (1572-1585). The dome of the chapel was used as a test to verify the feasibility of the main dome.
St. Peter's growth and history embrace nearly three hundred and fifty years, from the time of Nicholas V., who began it in 1450, to that of Pius VI, who built the sacristy in 1780; and it expresses, not only the will of different popes, the tastes of successive architects, but the changes and revolutions of time itself. (..) The whole cost of the building of St. Peter's from the foundation by Nicholas V. in 1450, to the completion of the sacristy by Pius VI. in 1780, is estimated to have been about forty-seven millions of dollars; a sum, representing, however, two or three times that amount in exchangeable value, at the present moment. This does not include any of the monuments or works of art.
George Stillman Hillard - Six Months in Italy in 1847-1848
The map here below shows under which pope the various parts of S. Pietro were completed and the whole page shows how the popes marked with their coats of arms or their heraldic symbols the parts which they had completed.
Map of S. Pietro and Piazza S. Pietro
Legend (the links go to the section of the page covering each pope):
Gregory XIII was the first pope who saw the completion of a part of S. Pietro. Cappella Gregoriana and the adjoining part of the right aisle are decorated with his formal coats of arms (in the pavement, walls, vault and in the balustrades of the altars). In addition the corridor leading to the right aisle houses the monument to him by Camillo Rusconi.
Dragon of Gregory XIII in the vault of the arch leading to Cappella Gregoriana
The decoration of the vault has a little surprise: at first sight it is decorated with golden cornucopias (horns of plenty) a traditional decorative theme; a closer look however shows that the end of the cornucopia is actually made up of a dragon, the heraldic symbol of the Pope. Learn more about it.
In 1586 Pope Sixtus V gave another important contribution to the design of Piazza S. Pietro by moving to the square in front of the old basilica a large obelisk which stood in the nearby Circus of Nero. The completion of the dome had been a nightmare for a long time (see how the basilica appeared in a 1588 Guide to Rome). There were serious doubts whether the drum would actually be able to support the weight of the dome and il Vignola and Giacomo della Porta, the architects in charge after Michelangelo of completing the dome preferred to concentrate on the completion of Cappella Gregoriana and its twin Cappella Clementina. The Pope was a very resolute character and in 1587 he asked Giacomo della Porta and his assistant Domenico Fontana to go ahead and complete the dome. The task, for the completion of which many thought ten years would not be enough, was completed in a couple of years and in 1590 Pope Sixtus V celebrated the event with a great ceremony.
Pope Sixtus V had a complex coat of arms with a lion holding pears and three mountains topped by a star. These symbols were used in the decoration of the drum of the dome and of the central line of windows. The plan for the basilica provided for a fašade very close to the dome; in this way the lions and the pears of the Pope would have had great visibility, which was eventually significantly reduced by the final layout of the Basilica and of the square. Learn more about the heraldic symbols of the Pope.
Pope Clement VIII was mainly involved in completing the decoration of the dome and of Cappella Clementina, named after him.
Coat of arms and heraldic symbols of Pope Clement VIII in Cappella Clementina
The decoration of Cappella Clementina followed the pattern of Cappella Gregoriana with a fine large mosaic showing the coat of arms of Clement VIII. In addition the walls were decorated with marble inlays showing the stars and the stripes of his coat of arms. Learn more about these heraldic symbols.
Pope Paul V had a major role in the completion of S. Pietro as he took the decision to modify the original project which was based on a Greek cross shape. S. Pietro was given a Latin cross shape by increasing the eastern nave, which was in some way attracted by the obelisk. Carlo Maderno built a new fašade which replaced the still surviving fašade of S. Pietro Vecchio.
Coat of arms of Pope Paul V by Martino Ferrabosco in the vault of the Portico
Formal coats of arms of the Pope were placed on the fašade, the vault of the Portico, the inner fašade and the vault of the nave (this coat of arms was replaced by a coat of arms of Pope Pius VI in 1780), but the eagles and the dragons of the Borghese, the family of the Pope, appear in many other places on the fašade and in the nave. Learn more about the Dragons and Eagles. The Pope was very proud of having reactivated an old Roman aqueduct and having brought a large amount of water (Acqua Paola) to the western part of Rome. This water was used to supply an existing fountain in Piazza S. Pietro which was renovated by Carlo Maderno in 1614 with the addition of the heraldic symbols of the Pope (the background of this page shows an eagle of the fountain).
Pope Urban VIII had a great admiration for Gian Lorenzo Bernini who was charged with the design of the decoration of the area below the dome. He envisaged four colossal statues inside niches in the lower part of the pillars supporting the dome.
The bees of Pope Urban VIII in the decoration of the pedestal of the statue of St. Helena
The niches had at their top the formal coats of arms of Pope Urban VIII, but Bernini made use of the heraldic symbol of the Pope (the bees) for the decoration of the pedestals of the statues. Bernini built also a gigantic Canopy which was decorated with eight puzzling coats of arms. The Pope had another heraldic symbol, the sun.
Pope Innocent X asked Bernini to design the pavement of the main nave and the decoration of its pillars.
The dove of Pope Innocent X in the decoration of the Nave
The Pope celebrated his rather minor contribution to S. Pietro by placing six gigantic coats of arms: three on the inner fašade (see one of them), two in the aisles and one on the pavement, but he also had his heraldic symbols (doves and fleurs-de-lis) used as a theme for the decoration of the pillars. Learn more on Where the Dove Flies.
Pope Alexander VII tackled the main remaining issue for the completion of S. Pietro and again Gian Lorenzo Bernini was asked to help. The square in front of the church was a rather haphazard assemblage of monuments (including a tower built by Martino Ferrabosco at the beginning of the century) which did not fit with the basilica. The Pope discussed personally with Bernini the various options and eventually endorsed the semicircular colonnades proposed by Bernini, both for their spiritual meaning (the arms of the Church embracing mankind) and for their effect in enhancing the vertical lines of the fašade. He also had Bernini decorate Scala Regia a new access to the Vatican, and design the Chair of St. Peter in the apse of the basilica.
The six mountains and the star (more on them) of Pope Alexander VII in the decoration of Scala Regia and in a candlestick
Six gigantic formal coats of arms of Alexander VII (see two of them) celebrate the completion of Piazza S. Pietro and four decorate the Chair of St. Peter (see one of them). The heraldic symbols of the Pope appear also in many other places in the basilica, including several candlesticks.
During the pontificate of Clement X, Gian Lorenzo Bernini was asked to design for the portico a pavement similar to that of the nave and to add another fountain to the existing one in Piazza S. Pietro. Both additions were celebrated with coats of arms.
Marble inlay depicting the coat of arms of Pope Clement X in the pavement of the Portico
Heraldic symbols of Pope Clement XI in the elliptical dome of Cappella del SS. Sacramento
The heraldic symbols of the Pope (three mountains and a star - more on them) appear in the lanterns of six elliptical domes which give light to the aisles. These lanterns are very high (see one of them on the roof of the basilica).
Pope Pius VI was eager to add his name to the list of the popes who built S. Pietro and he took the occasion of some restorations of the vault to replace the coat of arms of Paul V with his own. He actually made a large addition by building a sacristy. He also closed the issue of the bell towers of S. Pietro by putting on top of them two gigantic clocks designed by Giuseppe Valadier.
Heraldic symbols of Pope Pius VI in the northern clock by Valadier
The heraldic symbols of the Pope are not very evident, but two of them are there: three stars and plants of lilies. The one which is missing is Boreas, the cold north wind which blew over the lilies. Learn why The Wind was too Strong for poor Pope Pius VI.
The long pontificate of Pope Pius IX saw some minor additions to S. Pietro. When he reached in 1871 his 25th year in office the XIIIth century bronze statue of St. Peter was put under a sort of canopy topped by a portrait of the Pope because he had exceeded the term in office of the Apostle. In 1847 he replaced the existing statues of St. Peter and St. Paul in Piazza S. Pietro with larger ones. His coats of arms (usually of a small size) can be found in several places in the square and inside the basilica.
Coats of arms of Popes Pius IX and John Paul II on a candlestick and its candle