Vatican Secretariat of State

The Secretariat of State is the oldest dicastery in the Roman Curia, the central papal governing bureaucracy of the Catholic Church. It is headed by the Cardinal Secretary of State and performs all the political and diplomatic functions of the Holy See. The Secretariat is divided into two sections, the Section for General Affairs and the Section for Relations with States, known as the First Section and Second Section, respectively.

The origins of the Secretariat of State go back to the fifteenth century. The apostolic constitution Non Debet Reprehensibile of 31 December 1487 established the Secretaria Apostolica comprising twenty-four Apostolic Secretaries, one of whom bore the title Secretarius Domesticus and held a position of pre-eminence. One can also trace to this Secretaria Apostolica the Chancery of Briefs, the Secretariat of Briefs to Princes and the Secretariat of Latin Letters.

Pope Leo X established another position, the Secretarius Intimus, to assist the Cardinal who had control of the affairs of State and to attend to correspondence in languages other than Latin, chiefly with the Apostolic Nuncios (who at that time were evolving into permanent diplomatic representatives). From these beginnings, the Secretariat of State developed, especially at the time of the Council of Trent.

For a long time, the Secretarius Intimus, also called Secretarius Papae or Secretarius Maior, was almost always a prelate, often endowed with episcopal rank. It was only at the beginning of the pontificate of Innocent X that someone already a Cardinal and not a member of the Pope's family was called to this high office. Pope Innocent XII definitively abolished the office of Cardinal Nephew, and the powers of that office were assigned to the Cardinal Secretary of State alone.

On 19 July 1814, Pope Pius VII established the Sacred Congregation for the Extraordinary Ecclesiastical Affairs, expanding the Congregatio super negotiis ecclesiasticis Regni Galliarum established by Pius VI in 1793. With the apostolic constitution Sapienti Consilio of 29 June 1908, Saint Pius X divided the Sacred Congregation for Extraordinary Ecclesiastical Affairs in the form fixed by the Codex Iuris Canonici of 1917 (Can. 263) and he specified the duties of each of the three sections: the first was concerned essentially with extraordinary affairs, while the second attended to the ordinary affairs, and the third, until then an independent body (the Chancery of Apostolic Briefs), had the duty of preparing and dispatching pontifical Briefs.

...
Wikipedia