Vatican City, officially State of the Vatican City (Italian: Stato della Città del Vaticano), is a landlocked sovereign city-state whose territory consists of a walled enclave within the city of Rome. At approximately 44 hectares (110 acres), and with a population of around 800, it is the smallest independent state in the world by both population and area.
Vatican City is a city-state. It came into existence only in 1929. It is thus clearly distinct from the central authority of the Roman Catholic Church, known as the Holy See, which existed long before 1929. Ordinances of Vatican City are published in Italian. Official documents of the Holy See are issued mainly in Latin. The two entities even have distinct passports: the Holy See, not being a country, only issues diplomatic and service passports; the state of Vatican City issues normal passports. In both cases the number of passports issued is extremely limited.
The Lateran Treaty in 1929, which brought the city-state into existence, spoke of it as a new creation (Preamble and Article III), not as a vestige of the much larger Papal States (756-1870) that had previously encompassed central Italy. Most of this territory was absorbed into the Kingdom of Italy in 1860, and the final portion, namely the city of Rome with a small area close to it, ten years later, in 1870.
Vatican City is a non-hereditary, elected monarchy that is ruled by the Bishop of Rome — the Pope. The highest state functionaries are all clergymen of the Catholic Church. It is the sovereign territory of the Holy See (Sancta Sedes) and the location of the Pope's residence, referred to as the Apostolic Palace.
The Popes have resided in the area that in 1929 became the Vatican City only since the return from Avignon in 1377. Previously, they resided in the Lateran Palace on the Caelian Hill on the opposite side of Rome, which was out of repair in 1377. The signing of the agreements that established the new state took place in the latter building, giving rise to the name of Lateran Pacts, by which they are known.