If my understanding of its history is correct, in pre-Christian Rome the Vatican Hill was a site were various gods were worshiped. The neighborhood around the hill wasn’t really permanently settled during that period. Under the emperor Nero the hill was a site where many Christians, particularly St. Peter, were martyred. Constantine, after his conversion, built a basilica on the site dedicated to St. Peter. This stood until the 1500s when the current St. Peter’s Basilica was built. By the mid-800s the Pope had come to have temporal authority over Rome and much of Italy. The Papal States lasted for over 1,000 years until 1870 when Rome was taken by the new unified Kingdom of Italy. In 1929 Benito Mussolini and Pope Pius XI worked out a treaty which gave the church full sovereignty over the Vatican City while the Pope surrendered any claim to temporal authority outside the Vatican’s walls.

^^All 110 acres of it. Vatican City is 1/8 the size of Central Park and 1/7 the size of Phoenix Park.

The Lateran Palace was owned by an important Roman family as far back as 366 BCE. Through some political machinations, the Lateran eventually came under the direct control of the Emperor. When Constantine defeated Maxentius and assumed control over Rome, he presented the Pope Militiades with the Lateran Palace, which became the papal residence and seat of Christian governance.

Other donations followed, on the Italian peninsula, but also in the outlying provinces of the Roman Empire. The Church held all of these lands as a private landowner, not as a sovereign entity.During the 5th Century, the Church submitted to the sovereign authority of Ocacer, and later the Ostrogoths, while asserting spiritual primacy, through the Papacy of the Bishop of Rome, over the whole Church.

During the time of the reconquest of Italy by the Byzantine or Eastern Roman Empire (6th and 7th Centuries), the political infrastructure of Italy had pretty much disintegrated. The Papacy, as the largest and most influential landowner in the region, began to take on a lot of the ruling authority that the Byzantines were unable to exert in Rome and the surrounding areas. The Popes were technically Byzantine subjects, but in practicality, exercised great autonomy in ruling the Duchy of Rome.

That’s how it started. The Duchy or Rome evolved into a sovereign nation, known as the Papal States, which now has shrunk to the confined area known as Vatican City.

During medieval upheaval in Rome, the papal seat was relocated to Avignon, France. https://en.m.wikipedia.org/wiki/Avignon_Papacy

I really like that period of European history.

@cazzie Yes, although the Papal seat was in Avignon, there were still Papal lands in Rome. It was an air of increasing conflict between friendly factions and hostile factions, resulting in Pope Gregory XI’s decision to return the Papacy to Rome, in 1376–1377.

Cool period of Italian history. I’m sort of obsessed with Cola di Rienzo’s life and times.