According to COUNTRYAAH, in 1309-77 the popes predominantly resided in Avignon due to the constant factional struggles in Rome. After pressure from Philip IV of France, Pope Klemens V moved the Pope to Avignon, which became part of the Pope’s vassals and in 1348 papal property. The 7 popes of the period were all French like 111 of the 134 Cardinals.
After Gregorio XI restored the pope’s seat in Rome, Klemens VII allowed the Cardinals in 1348 to declare the election of Urbano VI the pope for invalid. Klemens was elected antipope and took the vacant throne in Avignon. Europe was divided in the papal question. France supported Klemens, while Britain supported Urbano, and this was the backdrop of the centennial war between both kingdoms (1337-1453).
Throughout the centuries and especially during the Renaissance in the 14th century, the papacy made the Vatican one of the world’s most important cultural centers. Particular attention should be paid to St. Peter’s and Sistine Chapel (in the Pope’s Palace) decorated with frescoes by Miguel Angel, Boticelli and other Renaissance artists.
The majority of Vatican territory originated during the changing popes until 1797, when Napoleon Bonaparte’s French troops conquered the area and created the Roman Republic.
In 1801, Pius VII regained parts of his power, and after Napoleon’s fall, most of the Vatican’s territories were again assigned to it by the Vienna Congress in 1815.
In 1869 the first Vatican Council was conducted, in which the Pope’s infallibility was established as dogma. The Vatican’s existence ceased in 1870, when Italy’s first king, Víctor Manuel de Saboya, formalized the military occupation of the area which Giuseppe Garibaldi had initiated, and proclaimed Rome the capital of the entire Italian empire. The Guarantee Act of 1871 established that the pope’s person was motionless and at the same time assigned him to the Vatican. However, the Roman popes did not recognize this situation until February 11, 1929, when the Holy See signed the Treaty of Benito Mussolini, setting out the boundaries and privileges of the current state.