Holy See
Although the Holy See is sometimes metonymically referred to as the "Vatican", the Vatican City State was distinctively established with the Lateran Treaty (1929) between the Holy See and Italy to ensure the temporal, diplomatic, and spiritual independence of the Papacy. As such, ambassadors are officially accredited to the Holy See and not the Vatican City State. Conversely, Papal nuncios to states and international organisations are recognised as representing the Holy See and the integrity of the Catholic Church along with its 1.3 billion members, not the Vatican City State, as prescribed also in the Canon law of the Catholic Church (1983). The "Holy See" thus refers to the See of Rome viewed as the central government of the Catholic Church. The Catholic Church, in turn, is the largest non-government provider of education and health care in the world, while the diplomatic status of the Holy See facilitates the access of its vast international network of charities.
Papal States
Despite the fact that the traditionally Catholic powers did not come to the pope's aid, the papacy rejected any substantial accommodation with the Italian Kingdom, especially any proposal which required the pope to become an Italian subject. Instead the papacy confined itself (see Prisoner in the Vatican) to the Apostolic Palace and adjacent buildings in the loop of the ancient fortifications known as the Leonine City, on Vatican Hill. From there it maintained a number of features pertaining to sovereignty, such as diplomatic relations, since in canon law these were inherent in the papacy. In the 1920s, the papacy – then under Pius XI—renounced the bulk of the Papal States, and the Lateran Treaty with Italy (then ruled by the National Fascist Party under Benito Mussolini) was signed on February 11, 1929, creating the State of the Vatican City, forming the sovereign territory of the Holy See, which was also indemnified to some degree for loss of territory.