Short answers, pulled from the story.
The Holy See is the central governing body of the Catholic Church and Vatican City. It encompasses the office of the pope as bishop of Rome and serves as the spiritual and administrative authority of the worldwide Catholic Church. Under international law it holds the status of a sovereign juridical entity.
The Holy See is the universal government of the Catholic Church, while Vatican City is the independent city-state from which it operates. The Vatican City State was established by the Lateran Treaty of 1929. The Holy See, not Vatican City, maintains diplomatic relations with states, and foreign embassies are accredited to the Holy See.
According to Catholic historical records and tradition, the Holy See was founded in the first century by Saint Peter and Saint Paul. The apostolic see of the Diocese of Rome was established in the 1st century.
The Holy See maintains bilateral diplomatic relations with 180 sovereign states. It also keeps 180 permanent diplomatic missions abroad, of which 74 are non-residential. During the 59 years it held no territorial sovereignty after 1870, its diplomatic relations grew from 16 states to 29.
The Holy See is administered by the Roman Curia, the central institutions assisting the pope. The Curia includes the Secretariat of State, nineteen dicasteries, three tribunals, eleven Pontifical Councils, and seven Pontifical Commissions. The Cardinal Secretary of State is its chief administrator, a role held by Cardinal Pietro Parolin since the 31st of August 2013.
The Pontifical Swiss Guard was founded by Pope Julius II in January 1506 as the personal bodyguards of the pope and continues that function. As of 2026 it has a fixed number of 135 members, who must be Catholic, unmarried Swiss males between the ages of 19 and 30 and at least 175 cm in height. It is listed in the Annuario Pontificio under Holy See.