One of the most prominent names in all of High Renaissance Italy and the most ambitious of all building projects in all of the 16th century; and yet, all we have of Bramante’s St Peter’s Basilica is an engraving on a coin and a floor plan. Physically, all that was built in Bramante’s time were the central piers, which ultimately proved to be spectacularly inadequate for the task and had to be enlarged and strengthened by successive generations.
Bramante, in his time, produced some of the most enduring features of modern European architecture. His iconic Tempietto, though symbolic rather than practical in nature, was copied widely in the 17th and 18th centuries. The palazzo Caprini, also known as Raphael’s House, set the blueprint for classical urban buildings across all of Europe and his Cortile de Belvedere marked the standard for successive courtyards.
Raphael’s House has since been demolished and the Cortile has been cut in half by the intrusion of a later wing. The largest of all his projects was finished over a 100 years after his death and to a design he would scarcely have recognized. Yet, the embryo of what the most important basilica in Catholic Christendom would come to look like still begins with Bramante and his project.
The first thing to note on the basis of the plan is that Bramante and the then-current pope Julius II sought a centrally planned building with the shape of a Greek cross. This was known long before the plan was ever found and is very much in accordance with Italian renaissance ideas. Leonardo da Vinci, who Bramante would have met in Milan, built no churches but made extensive sketches on the theme, and considered it a perfect type. His ideas were circulated widely but they were generally not in favour by the clergy. In fact, the only church in this period to be completed on the central principle is Santa Maria della Consolazione in Todi.
It has been suggested that the central plan is indicative of the humanistic spirit of renaissance thought and has been interpreted as a shift in philosophy from the celestial to the aspirations of this world. However, there is little to suggest that either Bramante or the pope, no matter their leanings towards ancient models, were in any way thinking along those lines. Instead, it is likely that Bramante saw the central plan as appropriate for a martyrium, i.e. a giant shrine to commemorate the supposed site of St. Peter’s tomb. Similarly, the Tempietto marks the spot of St. Peter’s crucifixion.
Given this relationship with the Tempietto, one could expect St. Peter’s Basilica to follow a similar line. However, judging by the engraving, that is not exactly what we find. Neither does the most admired of Roman structures, the Pantheon, with the exception of the dome, seem to provide more than a superficial resemblance.
Like Alberti’s San Sebastiano in Mantua, the classical language is almost entirely shorn of columns and expressed for the most part in flat pediments and occasionally in simple pilasters. The western front is preceded by a small domed chapel, similar to those by Brunelleschi in Florence. This chapel is flanked by two towers, bringing into play the possible influence of North European church architecture. Above rises a mighty hemi-spherical dome, presumably influenced by the Pantheon, but with a drum ringed with a columnar peristyle, much like the Tempietto. Chapels at the four corners of the structure are also crowned with small domes.
The multiplication of domes and the towers may suggest an attempt to surpass Hagia Sophia in Constantinople, which in the preceding century had fallen to the Turks. However, it is doubtful whether Bramante had any meaningful knowledge about this building. In any case, the minarets of the church on the Bosphorus were only added later, by the Turks. The possible connection is, nonetheless, an intriguing one. It is also possible that Bramante saw late-Roman churches as models.
Nothing like Bramante’s St. Peter’s was ever built but his designs did have an influence on contemporary buildings. For a sense of how the basilica might have looked like under Bramante’s guidance, the church of San Bagio in Montepulciano offers instructive clues. Only one of the towers was actually built in this case but if you can imagine a similar structure on a larger scale, with a heftier dome, with domed chapels at the corner and a domed chapel at the front gate, then suddenly, Bramante’s St. Peter’s nearly comes alive.