Foreword
The Historia Augusta (dating back to the early 4th century AD) starts with the biography of emperor Publius Aelius Hadrianus (76-138 AD), described as a ruthless, tough, and determined man of power, a man of multifaceted and versatile intellect, a great leader, and a master of propaganda to legitimize his own power and that of his successors.
But at the same time, he was a cultured man, a lover of the arts and beauty, and a great admirer of Greece, so much so that he was nicknamed Graeculus. He was fond of hunting and travel, curious about everything, a guardian of the ancient Roman cults as Pontifex Maximus, and at the same time an initiate of the Eleusinian Mysteries. He also had a weak, sentimental side that led him to "weep like a woman" over the death of his favorite Antinous.
Among his talents, the Historia Augusta records that he prided himself on being an expert in architecture, so much so that it is believed that Hadrian's Villa in Tivoli was designed by him.
Endless times scholars discussed the famous phrase describing the Villa, as well as over his rivalry and enmity with Apollodorus of Damascus, Trajan's great architect, who according to te legend mocked the Emperor because of the "umbrella domes" seen at Hadrian's Villa calling them "pumpkins," and was killed for that.
Leaving aside those legends passed down for centuries, the far more important thing is that Hadrian left us three extraordinary monuments that are immortal icons of ancient Roman architecture: the Pantheon, Hadrian's Villa, and the Mausoleum of Castel Sant'Angelo.
Three monuments that stand outside and above their category, whether they were temples, villas, or tombs. Their projects merged tradition and innovation, experimented with innovative building techniques, and had special relationships with the Light of the Sun. These illuminations had a seemingly hidden but actually very precise symbolic meaning, discovered, studied, and published in her books by Marina De Franceschini.
It is difficult to say to what extent Hadrian was an active designer of these three masterpieces as well as a commissioner, but we will examine them in this "trilogy" to show what they had in common, starting with the oldest and most outstanding one, the Pantheon.
The Pantheon
The first Pantheon, of which very few traces remain, was built in the 1st century BC by Marcus Vipsanius Agrippa, son-in-law of Augustus, perhaps as an Augusteum, a sort of temple dedicated to the then nascent Julio-Claudian dynasty.
The first Pantheon was destroyed by fire, and according to the Historia Augusta, Hadrian had it rebuilt, but left the original inscription with Agrippa's dedication on the pediment. A clever operation of image and propaganda: Hadrian showed his (false) modesty and, above all, linked himself to Augustus, because, like him, he had brought Rome back to its ancient splendor and a new Golden Age.
Today we know that construction of the current Pantheon was begun by Trajan, as evidenced by the discovery of brick stamps dating between 114 and 117 AD, and completed by Hadrian.
It has outstanding features, such as the grandiose unreinforced concrete dome, which still is the largest in the world (43 meters in diameter). It is therefore believed that the Pantheon was created by Apollodorus of Damascus, the only one capable of conceiving and realizing a project of such magnitude.
The secret of its solidity lies in the skillful use of building materials and the distribution of weight through large relieving arches inserted into the walls.
The only source of light is the large oculus, nine meters in diameter, which also serves as the keystone because the weights of the dome converge there.
Another well-known feature is that the Pantheon functioned like a giant spherical sundial. Every day at noon, the Sun's rays enter through the dome's oculus and create a Circle of Light directed toward the portal, whose height varies with the seasons.
Thus, throughout the year, various illuminations (hierophanies, i.e., sacred apparitions) can be observed in the Pantheon, each with a very specific symbolic meaning.
The most spectacular illumination, visible only on April 6th, 7th, and 8th or September 4th, 5th, and 6th, is the Arc of Light, discovered by Marina De Franceschini in 2014 and published with Giuseppe Veneziano in the book «Pantheon. Architecture & Light» (english edition also) published by Rirella Editrice.