Question: When did the location of the head of the catholic religion with a basilica named after the same saint as Mantua Cathedral become its own country?

Knowledge 1: Mantua Cathedral
Mantua Cathedral () in Mantua, Lombardy, northern Italy, is a Roman Catholic cathedral dedicated to Saint Peter. It is the seat of the Bishop of Mantua. [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: Mantua Cathedral
Mantua Cathedral () in Mantua, Lombardy, northern Italy, is a Roman Catholic cathedral dedicated to Saint Peter. It is the seat of the Bishop of Mantua. [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: Mantua Cathedral
Mantua Cathedral () in Mantua, Lombardy, northern Italy, is a Roman Catholic cathedral dedicated to Saint Peter. It is the seat of the Bishop of Mantua. [SEP] Knowledge 2: 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) [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''.

Answer: 11 February 1929