[11] It encompasses the office of the pope as the bishop of the Apostolic episcopal see of Rome and serves as the spiritual and administrative authority of the worldwide Catholic Church and the city-state.

[14] The Holy See is headquartered in, operates from, and exercises "exclusive dominion" over the independent Vatican City State enclave in Rome, of which the Pope is sovereign.

[16][17] The Roman Curia includes various dicasteries, comparable to ministries and executive departments, with the Cardinal Secretary of State as its chief administrator.

[note 3] In the Roman Catholic Church, only the see of the Pope bears the right to be addressed symbolically as "holy".

After the fall of the Western Roman Empire in 476, the temporal legal jurisdisction of the papal primacy was further recognised as promulgated in Canon law.

Yet, relations with the Kingdom of Italy and the Holy Roman Empire were at times strained, reaching from the Diploma Ottonianum and Libellus de imperatoria potestate in urbe Roma regarding the "Patrimony of Saint Peter" in the 10th century, to the Investiture Controversy in 1076–1122, and settled again by the Concordat of Worms in 1122.

Notwithstanding, the Holy See was represented in and identified as a "permanent subject of general customary international law vis-à-vis all states" in the Congress of Vienna (1814–1815).

Despite the Capture of Rome in 1870 by the Kingdom of Italy and the Roman Question during the Savoyard era (which made the Pope a "prisoner in the Vatican" from 1870 to 1929), its international legal subject was "constituted by the ongoing reciprocity of diplomatic relationships" that not only were maintained but multiplied.

The Lateran Treaty on 11 February 1929 between the Holy See and Italy recognised Vatican City as an independent city-state, along with extraterritorial properties around the region.

Since then, Vatican City is distinct from yet under "full ownership, exclusive dominion, and sovereign authority and jurisdiction" of the Holy See (Latin: Sancta Sedes).

Schools Relations with: The Holy See is one of the last remaining seven absolute monarchies in the world, along with Saudi Arabia, Eswatini, United Arab Emirates, Qatar, Brunei and Oman.

The Roman Rota handles normal judicial appeals, the most numerous being those that concern alleged nullity of marriage.

During this interregnum, the heads of the dicasteries of the Curia (such as the prefects of congregations) cease immediately to hold office, the only exceptions being the Major Penitentiary, who continues his important role regarding absolutions and dispensations, and the Camerlengo of the Holy Roman Church, who administers the temporalities (i.e., properties and finances) of the See of St. Peter during this period.

Canon law prohibits the College and the Camerlengo from introducing any innovations or novelties in the government of the church during this period.

[35] According to an article by David Leigh in the Guardian newspaper, a 2012 report from the Council of Europe identified the value of a section of the Vatican's property assets as an amount in excess of €680m (£570m); as of January 2013, Paolo Mennini, a papal official in Rome, manages this portion of the Holy See's assets—consisting of British investments, other European holdings and a currency trading arm.

Mennini heads a special unit inside the Vatican called the extraordinary division of APSA – Amministrazione del Patrimonio della Sede Apostolica – which handles the 'patrimony of the Holy See'.

The Holy See participates as an observer to African Union, Arab League, Council of Europe, the Non-Aligned Movement (NAM), Organization of American States, International Organization for Migration and in the United Nations and its agencies FAO, ILO, UNCTAD, UNEP, UNESCO, UN-HABITAT, UNHCR, UNIDO, UNWTO, WFP, WHO, WIPO.

In spite of some uncertainty among jurists as to whether it could continue to act as an independent personality in international matters, the Holy See continued in fact to exercise the right to send and receive diplomatic representatives, maintaining relations with states that included the major powers Russia, Prussia, and Austria-Hungary.

Where, in accordance with the decision of the 1815 Congress of Vienna, the Nuncio was not only a member of the Diplomatic Corps but its dean, this arrangement continued to be accepted by the other ambassadors.

In the course of the 59 years during which the Holy See held no territorial sovereignty, the number of states that had diplomatic relations with it, which had been reduced to 16, actually increased to 29.

[48] The State of the Vatican City was created by the Lateran Treaty in 1929 to "ensure the absolute and visible independence of the Holy See" and "to guarantee to it indisputable sovereignty in international affairs."

Archbishop Jean-Louis Tauran, the Holy See's former Secretary for Relations with States, said that Vatican City is a "minuscule support-state that guarantees the spiritual freedom of the Pope with the minimum territory".