Dominated by St. Peter's Basilica and its embracing colonnade, Vatican City covers 108.7 acres [44 hectares] on a site known to ancient Romans as Mons Vaticanus. Popes lost political power over Rome and the surrounding Papal States with the unification of Italy (1861-70) but remained in residence as self-styled ‘prisoners of the Vatican.’ Mussolini's government recognized Vatican City as an independent state in the 1929 Lateran Treaty. Operating its own bank, post office, pharmacy, and commissary, Vatican City employs nearly 2,000 people, mostly lay workers from Rome, and counts about 300 residents.

—From the National Geographic book Inside the Vatican, 1991