Carlo Gaetano Stampa was born on 1 November 1667 in
Milan to
count Cristiano
Stampa and Giustina of the
House of Borromeo. He was cousin to
Giuseppe Archinto,
Federico Visconti and nephew of
Federigo and
Saint Charles Borromeo. Carlo Gaetano entered in the
clerical state in his youth, he studied in Rome at the
Pontifical Roman Seminary and on 10 July 1698 he earned a
doctorate in utroque iure at the
University of Pavia. He took up a career as lawyer in Milan. In 1703 he moved to Rome where he entered in the administration of the
Papal States: in 1705 he became
referendary of the Tribunals of the
Apostolic Signature, on 10 December 1706 he was appointed Vice-
legate of
Romagna, a position he kept until 1709. Later he was governor of
Spoleto and from 1714 to 1717 he was governor of
Ancona, where he won a victory over the pirates. In 1716 he was appointed
Inquisitor in
Malta, but he never moved to such island. Carlo Gaetano was ordained
priest on 31 October 1717 and he was appointed
Titular archbishop of
Chalcedon on 6 December 1717, being consecrated
bishop on 23 Jan 1718 by Cardinal
Ferdinando d'Adda in Rome. From 1718 to 1720 he served as
Apostolic Nuncio to the
Grand Duchy of Tuscany and from 1720 to 1735 he served in the delicate position of
Nuncio to the
Republic of Venice. In 1735 he returned to Rome because on 12 December 1734
Pope Clement XII had appointed him Secretary of the
Congregation for Bishops. ==Archbishop of Milan==