Vatican City is the Holy See's independent city state, an enclave within Rome, Italy. The Vatican City State, also known as The Vatican, became independent from Italy with the Lateran Treaty (1929), and it is a distinct territory under "full ownership, exclusive dominion, and sovereign authority and jurisdiction" of the Holy See, itself a sovereign entity of international law, which maintains the city state's temporal, diplomatic, and spiritual independence. With an area of 49 hectares (121 acres) and a population of about 825, it is the smallest state in the world by both area and population. As governed by the Holy See, the Vatican City State is an ecclesiastical or sacerdotal-monarchical state (a type of theocracy) ruled by the pope who is the bishop of Rome and head of the Catholic Church. The highest state functionaries are all Catholic clergy of various national origins. After the Avignon Papacy (1309–1437), the popes have mainly resided at the Apostolic Palace within what is now Vatican City, although at times residing instead in the Quirinal Palace in Rome or elsewhere.
Within the Vatican City are religious and cultural sites such as St. Peter's Basilica, the Sistine Chapel, and the Vatican Museums. They feature some of the world's most famous paintings and sculptures. The unique economy of Vatican City is supported financially by donations from the faithful, by the sale of postage stamps and souvenirs, fees for admission to museums, and sales of publications.
The name "Vatican" was already in use in the time of the Roman Republic for the Ager Vaticanus, a marshy area on the west bank of the Tiber across from the city of Rome, located between the Janiculum, the Vatican Hill and Monte Mario, down to the Aventine Hill and up to the confluence of the Cremera creek.
Because of its vicinity to their arch-fiend, the Etruscan city of Veii (another naming for the Ager Vaticanus was Ripa Veientana or Ripa Etrusca) and for being subjected to the floods of the Tiber, the Romans considered this originally uninhabited part of Rome insalubrious and ominous.
The particularly low quality of Vatican wine, even after the reclamation of the area, was commented on by the poet Martial (40 – between 102 and 104 AD). Tacitus wrote, that in AD 69, the Year of the Four Emperors, when the northern army that brought Vitellius to power arrived in Rome, "a large proportion camped in the unhealthy districts of the Vatican, which resulted in many deaths among the common soldiery; and the Tiber being close by, the inability of the Gauls and Germans to bear the heat and the consequent greed with which they drank from the stream weakened their bodies, which were already an easy prey to disease".
The toponym Ager Vaticanus is attested until the 1st century AD: afterwards, another toponym appeared, Vaticanus, denoting an area much more restricted: the Vatican hill, today's St. Peter's Square, and possibly today's Via della Conciliazione.
Under the Roman Empire, many villas were constructed there, after Agrippina the Elder (14 BC–18 October AD 33) drained the area and laid out her gardens in the early 1st century AD. In AD 40, her son, Emperor Caligula (31 August AD 12–24 January AD 41; r. 37–41) built in her gardens a circus for charioteers (AD 40) that was later completed by Nero, the Circus Gaii et Neronis, usually called, simply, the Circus of Nero.
Opposite the circus was a cemetery separated by the Via Cornelia. Funeral monuments and mausoleums, and small tombs, as well as altars to pagan gods of all kinds of polytheistic religions, were constructed lasting until before the construction of the Constantinian Basilica of St. Peter in the first half of the 4th century. A shrine dedicated to the Phrygian goddess Cybele and her consort Attis remained active long after the ancient Basilica of St. Peter was built nearby. Remains of this ancient necropolis were brought to light sporadically during renovations by various popes throughout the centuries, increasing in frequency during the Renaissance until it was systematically excavated by orders of Pope Pius XII from 1939 to 1941. The Constantinian basilica was built in 326 over what was believed to be the tomb of Saint Peter, buried in that cemetery.
From then on, the area became more populated in connection with activity at the basilica. A palace was constructed nearby as early as the 5th century during the pontificate of Pope Symmachus (reigned 498–514).
Popes gradually came to have a secular role as governors of regions near Rome. They ruled the Papal States, which covered a large portion of the Italian peninsula, for more than a thousand years until the mid-19th century, when all the territory belonging to the papacy was seized by the newly created Kingdom of Italy.
For most of this time the popes did not live at the Vatican. The Lateran Palace, on the opposite side of Rome, was their habitual residence for about a thousand years. From 1309 to 1377, they lived at Avignon in France. On their return to Rome they chose to live at the Vatican. They moved to the Quirinal Palace in 1583, after work on it was completed under Pope Paul V (1605–1621), but on the capture of Rome in 1870 retired to the Vatican, and what had been their residence became that of the King of Italy.
In 1870, the Pope's holdings were left in an uncertain situation when Rome itself was annexed by the Piedmont-led forces which had united the rest of Italy, after a nominal resistance by the papal forces. Between 1861 and 1929 the status of the Pope was referred to as the "Roman Question".
Italy made no attempt to interfere with the Holy See within the Vatican walls. However, it confiscated church property in many places. In 1871, the Quirinal Palace was confiscated by the King of Italy and became the royal palace. Thereafter, the popes resided undisturbed within the Vatican walls, and certain papal prerogatives were recognized by the Law of Guarantees, including the right to send and receive ambassadors. But the Popes did not recognise the Italian king's right to rule in Rome, and they refused to leave the Vatican compound until the dispute was resolved in 1929; Pope Pius IX (1846–1878), the last ruler of the Papal States, was referred to as a "prisoner in the Vatican". Forced to give up secular power, the popes focused on spiritual issues.
