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.
Second Vatican Council
At the same time, the world's bishops faced challenges driven by political, social, economic, and technological change. Some of these bishops sought new ways of addressing those challenges. The First Vatican Council had been held nearly a century before but had been cut short in 1870 when the Italian Army entered the city of Rome at the end of Italian unification. As a result, only deliberations on the role of the papacy and the congruent relationship of faith and reason were completed, with examination of pastoral issues concerning the direction of the Church left unaddressed.