Along the Via Nomentana in Rome, in the monumental complex dedicated to Saint Agnese, there is the beautiful mausoleum of Santa Costanza. Basically we can consider it as a symbol of the Rome of the end the empire, a city which was changing its culture, religion and social balances. Over the centuries this wonderful building maintains its beauty, something that can make happy even a local tour guide.

The history of this extraordinary circular building dates back to 340 a.D. began when Constantina, the emperor Constantine's daughter, decided to create this huge building covered by a dome near the burial of Saint Agnes. The latter was a saint to whom Constantina was very devoted (according to tradition, moreover, it was precisely here that the Constantine's daughter looked after, miraculously, from a terrible disease, praying with devotion to Saint Agnes himself). So Constantine, exactly how other members of the aristocracy used to do even in the past, for the ordinary gods, donated to the woman who considered her patron saint a magnificent building. Furthermore the mausoleum took the name of Constance when Constantina, who in the meantime became a saint, was later called in this way when she changed her faith, becoming a christian believer.

What is really striking about the Mausoleum of Santa Costanza is, first of all, the structure of the mausoleum: circular, covered by a dome and punctuated by 12 pairs of columns arranged in a ring, with 12 windows that radiate light and shadow into the interior. A beautiful play of light that made the atmosphere sacred and mystical, in accordance with the architectural style of the time, in addition to the fantastic mosaics that covered the entire dome. Too bad that these mosaics were completely removed in 1620, when, unfortunately, they were in very bad condition. Fortunately for us, however, the mosaics of the 4th century a.D., which adorn the vault of the gallery outside the columns, have remained well preserved. We find naturalistic scenes, scrolls and vine shoots. Nature, therefore Life, represented in all its power and abundance. They are symbols already used by the pagans, for the christian perspective, which were later reused to display the salvation of God.

In the two niches that open along the outer ring, we also find two other mosaic scenes: the Traditio Legis  and the Traditio clavium. In the first one we see a beardless Christ, while handing a scroll to St. Peter (the scene is completed by St. Paul). Typical iconographic theme of early christian art, in which Jesus continues his evangelical mission by also sending his disciples to bring the Word of God. For example the Traditio Legis represented the official role of the church which have to evangelise, following the laws of Jesus. In the Traditio Clavium instead, Jesus hands the keys to St. Peter, making him the first pope of the newly formed Christian Church. It is from this episode, with the delivery of the Keys, that the concept for which St. Peter is recognized as the first pontiff in history is traced back. After all the Keys of St. Peter, still today, symbolize both the popes and the entire Vatican City. However these themes, widely visible through the mosaics, are also intertwined with the will, entirely imperial, to indissolubly link the religious power deriving from Christ with the political power of Constantine and his lineage. The emperor, the first to give freedom of worship to the christians with his Edict of Milan of 313 a.D. (also drawn up by Licinius, emperor of the Eìeastern empire), and his family became guarantors of Christianity, becoming its most strenuous defenders, and giving a decisive impetus to the development, also in an architectural sense, of the Christian community.

Thanks to this extraordinary mausoleum and its decorative apparatus, therefore, it is easy to recognize a double path: on the one hand, as early Christian art itself, already in the fourth century a.D. taking hold even in the higher classes of Roman society, which has recently become almost accustomed to the presence, free and in the light of the sun, of Christianity. On the other hand, it is understood how, perhaps for the first time with so much strength, not only an emperor like Constantine but his whole family had taken on, even symbolically and architecturally, the destiny of that new faith which, in one way or the other, they made the emperor's own fortune. With the Mausoleum of Santa Costanza, in short, in an intertwining of politics, religion and art, you can really get in touch with a century, the IV a.D., a harbinger of social changes and evolutions.