Lateran Treaty
Negotiations for the settlement of the Roman Question began in 1926 between the government of Italy and the Holy See, and culminated in the agreements of the Lateran Pacts, signed—the Treaty says—for King Victor Emmanuel III of Italy by Benito Mussolini, Prime Minister and Head of Government, and for Pope Pius XI by Pietro Gasparri, Cardinal Secretary of State, on 11 February 1929. It was ratified on 7 June 1929. The agreements were signed in the Lateran Palace, hence the name by which they are known.
Black nobility
Following the conclusion of the Lateran Treaty in 1929, the Black Nobility were given dual citizenship in Italy and Vatican City. Under the provisions of the treaty, noble titles granted by the pope were recognized in the Kingdom of Italy. Many of these families were members of the largely ceremonial Papal Noble Guard; others were foreigners affiliated with the Holy See in various ways. In 1931, Pope Pius XI denied the request of Alfonso XIII of Spain to open the Noble Guard further to nobles from all Catholic countries. In World War II, the Papal Noble Guard guarded the Pope alongside the Swiss Guard.