After his time as a diplomat, Caracciolo had a high political career, spending five years as viceroy of Sicily. He was appointed to the post in May 1780 but only took it up in 1781, since he was reluctant to leave Paris for Sicily. His experience of the French Enlightenment led him a policy of opening up reforms as viceroy. This brought him into open and sometimes successful conflict with the privileges of the aristocracy and clergy, in which he was supported by some of the middle class, who were more inclined to support the monarchy's moderate reform policy. For example, he had the collaboration of Naples' Inquisitor General, the reforming bishop Ventimiglia, in abolishing the Holy Office. He managed to establish new rules for the administration of justice and feudal common lands. For various reasons, including the terrible earthquakes that devastated Messina in 1783, he had to give up on what he considered the most important reform – the creation of a class in which at first sight seemed to be described and designated property by its borders, cultures and annuities, a basic and essential preliminary to a taxation feudal and ecclesiastical estates