When Italian troops entered Rome in 1870 and absorbed the last of the Papal States, Pius IX refused to recognize the new kingdom, declined its offers of compensation, and did not leave the Vatican again. His successors kept the same position for nearly sixty years: no pope appeared publicly in Rome, Catholics were discouraged from voting in Italian national elections, and the pope's status in international law was undefined. This standoff was known as the Roman Question, and it made the papacy a resident of a state it did not acknowledge.
Pius XI settled it. Negotiations begun in 1926 produced the Lateran agreements, signed in February 1929: a treaty recognizing the full sovereignty of the Holy See over the 44 hectares of Vatican City, a financial convention compensating for the lost territories, and a concordat regulating the church's position in Italy, including religious instruction in schools and the civil recognition of church marriages. The pope emerged onto the balcony and the loggia of Saint John Lateran for the first time in the modern era.
The settlement was made with Mussolini's government, and that is the standing criticism of it. It gave the fascist regime international prestige at a moment when it was consolidating power, and Pius XI in one remark called Mussolini a man sent by providence, a phrase quoted against him ever since. His own conduct afterwards complicates the picture: within two years he issued Non Abbiamo Bisogno, written in Italian rather than Latin so it could be read directly by Italians, attacking the regime for suppressing Catholic Action and for claiming the total allegiance of the young.