Between 1569 and 1582, the inquisitorial court of the Cardinal Archbishop of Naples undertook a series of trials against a powerful and wealthy group of Spanish immigrants in Naples for judaizing, the practice of Jewish rituals. The immense scale of this campaign and the many complications that resulted render it an exception in comparison to the rest of the judicial activity of the Roman Inquisition during this period. In Naples, judges employed some of the most violent and arbitrary procedures during the very years in which the Roman Inquisition was being remodeled into a more precise judicial system and exchanging the heavy handed methods used to eradicate Protestantism from Italy for more subtle techniques of control.

The history of the Neapolitan campaign sheds new light on the history of the Roman Inquisition during the period of its greatest influence over Italian life. Though the tribunal took a place among the premier judicial institutions operating in sixteenth century Europe for its ability to dispense disinterested and objective justice, the chaotic Neapolitan campaign shows that not even a tribunal bearing all of the hallmarks of a modern judicial system—a professionalized corps of officials, a standardized code of practice, a centralized structure of command, and attention to the rights of defendants—could remain immune to the strong privatizing tendencies that undermined its ideals.