Italian cardinal; papal legate; secretary of state (1769). prefect of the S.C. of the Tridentine Council substituting for Cardinal Carlo Vittorio Amedeo delle Lanze, who was habitually absent in Piedmont; and at the death of the cardinal on January 23, 1784, he was named pro-prefect of that congregation. Camerlengo of the Sacred College of Cardinals, January 29, 1776 until February 17, 1777. Protector of the Order of Preachers (Dominicans) in January 1781. Ambassador plenipotentiary to conclude the treaty with Venice, October 3, 1783.
 
ALS - AUTOGRAPH LETTER SIGNED, 19 March 1783, two sides of folio, written as Prefect of the Sac. Congr. of the Tridentine.  Addressed to the vice-legate of Avignon and concerns the examination, verification and settlement of disputes that arose between commissioners of the Papal States and representatives of the King of France. This is a document of historical and administrative interest written on the eve of the French Revolution. Merits further research.