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.
Christianity in the 19th century
The doctrine of papal primacy was further developed in 1870 at the First Vatican Council, which declared that "in the disposition of God the Roman church holds the preeminence of ordinary power over all the other churches". This council also affirmed the dogma of papal infallibility, (declaring that the infallibility of the Christian community extends to the pope himself, when he defines a doctrine concerning faith or morals to be held by the whole Church), and of papal supremacy (supreme, full, immediate, and universal ordinary jurisdiction of the pope).