03 May Completely divine. (1)
The early transformation to the Christian basilica (Santa Maria dei Martiri) in 609 allowed the Pantheon complex to survive as no other monument of ancient Rome, preserving it from the ruin and plundering suffered by classical buildings in successive ages. In fact, it is on of the best preserved testimony of Roman civilization, and it is like no other an example of the stratification and continuity from the classical world to Christianity, from the Risorgimento to the present day, which gives its uniqueness to the city of Rome.
The Pantheon, name with Greek origin, appears for the first time in Dione Cassio (155-229 BC), a temple already built, and indicates the sacred buildings dedicated to the divinized Kings (and their gods protectors) in use in the Hellenic kingdoms. His etymology alludes to something entirely (παν) divine (θεός), or devoted to all gods.
Dione Cassio opted for the first meaning, influenced by the prodigious dome that made the light penetrate through the large central hole.
It is thought that the building was originally dedicated to the Gens Julia triad, namely Mars – Venus – Divo Julio. Julius Caesar’s posthumous divinity was set by Augustus to a Senate who was definitely bothered by such a Hellenistic practice. For the Romans in fact, religion was a conspicuous element of politics, which contributed to the success of the Empire as much as political decisions, but did not play a prominent role. In short, for the Romans, religion consisted essentially in keeping the gods good enough not to compromise the fulfillment of Rome’s dominant destiny (the pax deorum, the community of intentions between the gods and Rome).
The inscription on the architrave, Marcus Agrippa Luci Filius Consul Terzium fecit (Marco Agrippa, son of Lucio, built it in his third consulate) refers to a first version built by the faithful companion of Ottaviano (more or less in 25 BC). It became edible after the definitive victory over Antonio and Cleopatra. He is the author, among other things, of the aqueduct basement of Acqua Vergine, still working today to feed important monuments in the area, including the Trevi Fountain.
The temple was seriously damaged by a fire in 80 dC. and was completely reconstructed by Adriano between 118 and 125 in the form we came to, probably on his own project, which restored the inscription according to his principle of not leaving evidence of his work, as happened for all buildings built from him with the only exception of the Temple dedicated to his adoptive father Trajan.
As mentioned earlier, the idea of the oculus, the central hole of the dome, refers to the sun and the sky as the unifying and omnipresent elements of religions practiced throughout the Empire, witnessing the profound tolerance that the Romans had towards the religions of the subjugated peoples, also free to follow the cultures they preferred, provided they did not threaten the pax deorum.
Whether it is a further tribute to the Sun, or perhaps a desire to create a sense of extreme harmony between the proportions, the diameter/circumference of the circular dome is perfectly equal to the height of the overall building, and a sphere can be ideally inscribed in the building. But the extraordinary features of the building do not stop here.
The dome, 43.40m in diameter, is still the biggest ever made of concrete (St. Peter’s is smaller than half a meter). An engineering masterpiece that was based on a progressive reduction in concrete thickness, mixed with tuff and volcanic debris to give it more lightness. The concrete thickness starts at the base at 6 meters and arrives at 1.40 meters at the oculus.
Unfortunately, there are no documents handed down to clarify the method used to lift the workers during the construction of the dome, probably a large centering, over 30 meters high, on the roof.
The dome was entirely lined with polished and golden bronze, to recall the bond with the cult of the sun, and had to stir up on those who saw it for the first time a surprising effect. The Pantheon appeared at the end of a large avenue enclosed by colonnaded porches, travertine pavement, along the double of the space occupied today by the Rotonda Square. Almost certainly that bronze can be found today in some statue or furnishings of Roman noble houses or churches, given the custom in subsequent centuries of spoiling classical works of their riches. To increase the aerial perspective, the interior of the dome is decorated by five progressively narrower coffered rings, originally embellished with golden bronze frames as well.
In the second part, we will discuss the rather long and troubled transition from a Roman church to a Christian church.