 He spent many years working on commissions charged with revising the education and discipline of the clergy, serving on diplomatic missions for the Holy See, attending the Council of Trent, at which he played an important role, and as head of the principal Theatine house in Rome.Perhaps his most important accomplishment was in helping to prevent the establishment of the Spanish Inquisition in Naples, a matter about which the Neapolitans were very adamant.Neapolitan feelings about the Spanish Inquisition were so strong that a baronial rebellion in 1547 liberated hundreds of people from inquisititorial prisons.