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.
View of St. Peter’s Square from the top of Michelangelo’s dome
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.
An interpretation of the relative locations of the circus, and the medieval and current Basilicas of St. Peter.
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).
Papal States:
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 createdKingdom 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.
The Italian peninsula in 1796. The Papal States in central Italy are colored purple.
Italian unification:
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”.
