State of the Vatican City is a city-state whose territory consists of an enclave within the city of Rome in the Italian peninsula . It is one of six European microstates . The Town that properly Vatican has an area of 0,439 km ² (44 acres ) in January and a population of about 900 inhabitants, 2 so it is a hybrid of city elevated to state independent, and is the world's smallest country, and which is the only official language Latin . It is so small that only St. Peter is 7% of its surface, the Basilica and St. Peter's Square occupy 20% of the territory, making it the world's most urbanized independent territory. Vatican City came into existence in 1929 after the signing of the Lateran Treaty concluded between the Holy See and the then Kingdom of Italy , which in 1870 had conquered the Papal States.