When Rome was annexed in 1870, Pope Pius IX (1792-1878) declared himself a prisoner in the Vatican city and refused recognition of unification.
In 1874, the pontiff forbade Catholics to participate in the election that would vote for the new parliament. This mismatch between the Italian government and the Vatican was called "Roman Question".
The problem persisted until 1920 and was solved with the signing of the Lateran Treaty during the government of Benito Mussolini.
Under the treaty, the government would indemnify the Catholic Church for the loss of Rome, grant it sovereignty over St. Peter's Square and recognize the Vatican State as a new nation whose Head of State was the Pope.
For his part, the pontiff recognized Italy and its government as an Independent State
The unification of Italy was a process of union between the various kingdoms that made up the Italian Peninsula, after the expulsion of the Austrians. It occurred in the second half of the 19th century and ended in 1871.
With this, the kingdoms started to form a single country, the Kingdom of Italy, under the reign of Victor Manuel II.
The late process resulted in the delay of Italian industrial development and the rush to occupy territories in Africa.
