Vatican City
The name was first used in the Lateran Treaty, signed on 11 February 1929, which established the modern city-state. The name is taken from Vatican Hill, the geographic location of the state. "Vatican" is derived from the name of an Etruscan settlement, "Vatica" or "Vaticum" meaning garden, located in the general area the Romans called "vaticanus ager", "Vatican territory".
Holy See
The apostolic see of Rome was established in the 1st century by Saint Peter ("Prince of the Apostles") and Saint Paul, then the capital of the Roman Empire, according to Catholic tradition. The legal status of the Catholic Church and its property was recognised by the Edict of Milan in 313 by Roman Emperor Constantine the Great, and it became the state church of the Roman Empire by the Edict of Thessalonica in 380.