Vatican City is not a City, it is a Country
The Vatican city, occupying an area of only 0.44 sq km, was built within the territory of Rome (capital of Italy) in 1929 with the purpose to establish and safeguard the clergymen. It is a landlocked sovereign city-state whose territory consists of a walled enclave within the city of Rome. The Roman clergyman (who have highest rank among the Popes) runs the affairs of the city and serve their religion. The Apostolic Palace (also known as the Sacred Palace, the Papal Palace and the Palace of the Vatican) is the official residence of the Pope. The country has a total population of around 800 priests. A panel called the pontifical commission for Vatican City state elect the Pope for the five year period and the Pope acts as a sovereign in their decision making during that time period.