Question: When did the location of the basilica named after the apostle crucified upside down become its own country?

Knowledge 1: Saint Peter
According to Christian tradition, Peter was crucified in Rome under Emperor Nero Augustus Caesar. It is traditionally held that he was crucified upside down at his own request, since he saw himself unworthy to be crucified in the same way as Jesus. Tradition holds that he was crucified at the site of the Clementine Chapel. His remains are said to be those contained in the underground Confessio of St. Peter's Basilica, where Pope Paul VI announced in 1968 the excavated discovery of a first - century Roman cemetery. Every 29 June since 1736, a statue of Saint Peter in St. Peter's Basilica is adorned with papal tiara, ring of the fisherman, and papal vestments, as part of the celebration of the Feast of Saints Peter and Paul. According to Catholic doctrine, the direct papal successor to Saint Peter is the incumbent pope, currently Pope Francis. [SEP] Knowledge 2: St. Peter's Basilica
The Papal Basilica of St. Peter in the Vatican (Italian: Basilica Papale di San Pietro in Vaticano), or simply St. Peter's Basilica (Latin: Basilica Sancti Petri), is an Italian Renaissance church in Vatican City, the papal enclave within the city of Rome. [SEP] Knowledge 3: Vatican City
The name Vatican city 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''.
Knowledge 1: Saint Peter
According to Christian tradition, Peter was crucified in Rome under Emperor Nero Augustus Caesar. It is traditionally held that he was crucified upside down at his own request, since he saw himself unworthy to be crucified in the same way as Jesus. Tradition holds that he was crucified at the site of the Clementine Chapel. His remains are said to be those contained in the underground Confessio of St. Peter's Basilica, where Pope Paul VI announced in 1968 the excavated discovery of a first - century Roman cemetery. Every 29 June since 1736, a statue of Saint Peter in St. Peter's Basilica is adorned with papal tiara, ring of the fisherman, and papal vestments, as part of the celebration of the Feast of Saints Peter and Paul. According to Catholic doctrine, the direct papal successor to Saint Peter is the incumbent pope, currently Pope Francis. [SEP] Knowledge 2: St. Peter's Basilica
The Papal Basilica of St. Peter in the Vatican (Italian: Basilica Papale di San Pietro in Vaticano), or simply St. Peter's Basilica (Latin: Basilica Sancti Petri), is an Italian Renaissance church in Vatican City, the papal enclave within the city of Rome. [SEP] Knowledge 3: Old St. Peter's Basilica
St. Peter's Basilica Basilica Sancti Petri 19th - century drawing of St. Peter's Basilica as it is thought to have looked around 1450. The Vatican Obelisk is on the left, still standing on the spot where it was erected on the orders of the Emperor Caligula in 37 A.D. Basic information Geographic coordinates 41 ° 54 ′ 8 ''N 12 ° 27 ′ 12'' E ﻿ / ﻿ 41.90222 ° N 12.45333 ° E ﻿ / 41.90222; 12.45333 Coordinates: 41 ° 54 ′ 8 ''N 12 ° 27 ′ 12'' E ﻿ / ﻿ 41.90222 ° N 12.45333 ° E ﻿ / 41.90222; 12.45333 Affiliation Roman Catholic Country Papal States Year consecrated c. 360 Ecclesiastical or organizational status Major basilica Architectural description Architectural style Ancient Roman architecture Groundbreaking 326 - 333 (326 - 333) Completed c. 360 (c. 360)
Knowledge 1: Saint Peter
According to Christian tradition, Peter was crucified in Rome under Emperor Nero Augustus Caesar. It is traditionally held that he was crucified upside down at his own request, since he saw himself unworthy to be crucified in the same way as Jesus. Tradition holds that he was crucified at the site of the Clementine Chapel. His remains are said to be those contained in the underground Confessio of St. Peter's Basilica, where Pope Paul VI announced in 1968 the excavated discovery of a first - century Roman cemetery. Every 29 June since 1736, a statue of Saint Peter in St. Peter's Basilica is adorned with papal tiara, ring of the fisherman, and papal vestments, as part of the celebration of the Feast of Saints Peter and Paul. According to Catholic doctrine, the direct papal successor to Saint Peter is the incumbent pope, currently Pope Francis. [SEP] Knowledge 2: Vatican City
The name Vatican city 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''. [SEP] Knowledge 3: The Vision of Constantine (Bernini)
The Vision of Constantine is an equestrian sculpture by the Italian artist Gian Lorenzo Bernini, located in the Scala Regia by St. Peter's Basilica in Vatican City. Originally commissioned as a free standing work of art within St. Peter's itself, the sculpture was finally unveiled in 1670 as an integral part of the Scala Regia - Bernini's redesigned stairway between St. Peter's Basilica and the Vatican Palace. Unlike other large works by Bernini, art historians have suggested that this work was almost entirely undertaken by him - no other sculptors have been recorded as receiving payment. Bernini's overall fee was 7,000 Roman scudi.

Answer: 11 February 1929