From 1591 to 1595, Olivares was appointed viceroy of Sicily. In November 1595, Philip II appointed Olivares viceroy of Naples. His time in Naples is noted for its abundant crops; Olivares' vigorous attempts to suppress banditry in Naples; and a building program sponsored by Olivares utilizing the services of architect Domenico Fontana. During his service in Sicily, Olivares strengthened the coast against Ottoman and berbary pirates attacks, and lead successful raiding on Ottoman ship in the area and, numerous bombing of Tripoli, Misrata, Tunis and Alger for which he was rewarded. Upon the death of Philip II in 1598, Philip III of Spain confirmed Olivares as Viceroy of Naples. Historians of that time give him high marks for his service in Italy as ambassador and viceroy.
