The Vatican City State (Stato della Città del Vaticano) is a walled enclave within the city of Rome. It is the smallest internationally recognised independent state in the world by both area and population. It is an ecclesiastical or sacerdotal-monarchical state ruled by the Bishop of Rome, the Pope. The highest state functionaries are all Catholic clergy of various national origins. Since the return of the Popes from Avignon in 1377, they have generally resided at the Apostolic Palace within what is now Vatican City although at times residing instead in the Quirinal Palace in Rome or elsewhere. Please note that the Vatican City is distinct from the Holy See, which dates back to early Christianity and is the main episcopal see of about 1.2 billion Latin and Eastern Catholic adherents around the globe. The independent city state, on the other hand, came into existence in 1929 when the Lateran Treaty between the Holy See and the Kingdom of Italy was signed by Prime Minister and Head of Government Benito Mussolini on behalf of King Victor Emmanuel III and by Cardinal Secretary of State Pietro Gasparri for Pope Pius XI. According to the terms of the treaty, the Holy See has “full ownership, exclusive dominion, and sovereign authority and jurisdiction” over the city state.