Question: When did the location of the Basilica that is named after the same saint as the Schleswig Cathedral and the head of the catholic religion become its own country?

Knowledge 1: Schleswig Cathedral
Schleswig Cathedral (, ) officially the Cathedral of St. Peter at Schleswig (), is the main church of the city of Schleswig and was the cathedral of the Bishop of Schleswig until the diocese was dissolved in 1624. It is now a church of the North Elbian Evangelical Lutheran Church, the seat of one of its bishops, and ranks among the most important architectural monuments of Schleswig-Holstein. [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: Schleswig Cathedral
Schleswig Cathedral (, ) officially the Cathedral of St. Peter at Schleswig (), is the main church of the city of Schleswig and was the cathedral of the Bishop of Schleswig until the diocese was dissolved in 1624. It is now a church of the North Elbian Evangelical Lutheran Church, the seat of one of its bishops, and ranks among the most important architectural monuments of Schleswig-Holstein. [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''.
Knowledge 1: Schleswig Cathedral
Schleswig Cathedral (, ) officially the Cathedral of St. Peter at Schleswig (), is the main church of the city of Schleswig and was the cathedral of the Bishop of Schleswig until the diocese was dissolved in 1624. It is now a church of the North Elbian Evangelical Lutheran Church, the seat of one of its bishops, and ranks among the most important architectural monuments of Schleswig-Holstein. [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)

Answer: 11 February 1929