Uncovering the Vatican Hill from Roman Emperors to Popes

Today, through a new high-tech Microsoft-sponsored project, which has sponsored this video, we'll explore the Vatican Hill from its Roman imperial beginnings, the tomb of St. Peter's, the Constantinian Basilica Church, and finally, St. Peter's that still stands today, rich in details and layered in history. Let's dive into this phenomenal project. St. Peter's is one of the artistic treasures of the world. There's so much to preserve, and there's so much to share. And now through a new project using AI and photogrammetry, Microsoft has teamed with the Vatican and Aconum to digitally preserve St. Peter's. And this is incredible as a learning opportunity, as an opportunity to explore this rich past. We'll be able to start from the original hill, Mons Vaticanus, all the way forward in time to St. Peter's today. It's an extraordinary opportunity. First we can journey back to the beginning of the Mons Vaticanus, located in the Transtibrium region of Rome, and is across the Tiber River from central Rome. It was located in a marshy area dominated by the Vatican Hill. In the late Republican and early Imperial period, the area became a zone filled with patrician properties, eventually dominated by the garden estates, known as Horti. In particular, the Horti of Agrippina, the mother of Caligula. When he became emperor, Caligula further developed his family property and transformed a portion of it into a private chariot racing circus distinct from the public Circus Maximus by the Palatine. The most noteworthy feature was the enormous obelisk that Caligula brought from Egypt to decorate his circus in imitation of the obelisk that Augustus brought to the Circus Maximus, today located in the Piazza del Popolo. This obelisk of Caligula, weighing over 300 tons, is still a key feature of the Vatican and St. Peter's today. Afterward, the Emperor Nero further developed the gardens. He built a private theater on the property nearby. Its remains were recently rediscovered in 2021. Nero also used the Circus of Caligula. It was here that he punished Christians, whom he blamed for the fire of 64, which ravaged most of Rome. According to tradition, Peter was crucified here and buried in the adjacent necropolis on the Via Cornelia. There are other necropolises discovered, such as the portion found in the Vatican Santa Rosa car park along the nearby Via Triumphalis. The dead were traditionally buried outside the city limits, and the Vatican Hill became a popular spot for burials over the centuries in many locations. In fact, the most noteworthy monument of the Via Cornelia necropolis was this large Severan era mausoleum constructed within the area of the then defunct circus right next to the obelisk. This domed hall would go on to resist the test of time and would be converted into a Christian hall known as the Church of Santa Maria della Febbre and was only destroyed in 1777. With Constantine's defeat of Maxentius at the Milvian Bridge on October 28, 312, the Roman world would dramatically change. Constantine legalized Christianity in 313 with the Edict of Milan. In Rome, this led to massive new building projects, including the construction of St. Peter's on top of the traditional location of Peter's tomb on the Via Cornelia within the neighborhood of the Circus of Caligula in Nero. This structure was a new definitive statement of the presence and legalization of the Christian God in Rome. The Basilica Church, modeled after the basilica or law court architecture of the Roman Forum, was a massive hall to accommodate believers. It was in use for over a thousand years and witnessed countless pilgrimages, papal coronations, and the crowning of Charlemagne in 800. After Constantine, we move on to the Emperor Theodosius, who died at 395, leaving an empire divided, Arcadius in Constantinople, while Honorius, his brother, ruled in the west. Honorius actually resided in Milan as the western capital at that time, but Rome remained an essential city, and thus he constructed a family mausoleum right next to St. Peter's and the Severan era tomb. Honorius' impressive mausoleum was later known as the Chapel of St. Petronila. These two mausoleum structures, and the obelisk, withstood for a time and witnessed a rapidly changing Rome, subsumed beneath dramatic conflict. The Sack of 410, the Sack of 455, and the devastating Gothic Wars that saw the city's population dramatically decline. Still, St. Peter's remained a focal point in Rome. But by the early 16th century, it was decided to reconstruct St. Peter's, along with the expansion of the Vatican residence. This epic undertaking, begun in 1506, would not be completed until 1626. This led to the destruction of the Honoran Mausoleum, as well as the eventual relocation of the obelisk from the Circus of Nero by Dominican Fontana in 1586. The project would include the work of some of the greatest artists and architects, including Bramante, Michelangelo, Fontana, and Bernini. And it's new St. Peter's that now resists the test of time, with its stunning exterior and interior accommodating millions of tourists and pilgrims each year. And it was in need of a new study and new preservation efforts. The Vatican, with Microsoft and Econom, has created a new, innovative way to share its rich heritage with the world, especially timely for the pilgrims and the 2025 Jubilee. The study was meticulous and multi-layered. It wasn't just a record of the condition of St. Peter's, but it also allows you, the visitor, to look at details and spaces otherwise impossible to fathom. Let's admire the expansive vaulting of the nave, indebted to the vaulted halls of the great public bath complexes of Caracalla and Diocletian. We can also better appreciate the scale and details of Bernini's Baldacchino, the massive bronze sculpture made from the bronze melted down from the porch roofing of the Pantheon. Documented by Borromini, it was an estimated 156 tons of bronze melted down and reused in part to make this, a one-of-a-kind canopy over the high altar where only the Pope holds mass. There are new 3D models and educational content to explore on a new interactive website that is so amazing you'll gain special access and views of details of mosaics and frescoes and sculptures in locations normally inaccessible. And that's my kind of history. It's a true gateway for the exploration of the site, for the teacher, the student, the pilgrim. Besides the website, in St. Peter's itself, there is also a really cool AI-powered Petrus Eni exhibition, which presents historical insights and digital exploration of the history of the Church with a unique blend of historical insight and digital exploration, showcasing key architectural and cultural aspects of the Basilica. It offers a cutting-edge experience that combines physical and digital interaction that deepens the connection to the site's history. The digital project isn't just educational. It has also yielded new discoveries, such as identifying structural vulnerabilities like missing mosaic tiles and fissures that provide valuable data for future restoration efforts. And that's what it's really all about. That's where we should begin to implement the new technologies, not just for documentation, but to allow us to have more critical insights of these monuments to positively impact on them for their longevity before any problems arise. St. Peter's stands today with incredible historical, architectural, cultural, spiritual significance. From the colonnades of Bernini to the imposing obelisk brought here for a circus in ancient Roman times, to the imposing façade of St. Peter's itself, and the dome designed by Michelangelo, standing today 448 feet tall. This is incredible history, and thanks to Microsoft and the Vatican, we now have the opportunity to explore this imposing history online and in great detail.