Pope Paul IV, C.R. (Latin: Paulus IV), born Gian Pietro Carafa, was head of the Catholic Church and ruler of the Papal States from 23 May 1555 to his death in 1559. While serving as papal nuncio in Spain, he developed an anti-Spanish outlook that later coloured his papacy, and resulted in the Papal States suffering a serious military defeat in the Italian War of 1551-59.
Carafa was appointed bishop of Chieti, but resigned in 1524 in order to found with St. Cajetan the Congregation of Clerics Regular (Theatines). Recalled to Rome, and made Archbishop of Naples, he was instrumental in setting up the Roman Inquisition, and was opposed to any dialogue with the emerging Protestant party in Europe. Carafa was elected pope in 1555 through the influence of Cardinal Alessandro Farnese in the face of opposition from Emperor Charles V. His papacy was characterized by strong nationalism in reaction to the influence of Philip II of Spain and the Habsburgs. He compelled the Jews of Rome to wear distinctive clothing and confine themselves to a ghetto. The appointment of Carlo Carafa as Cardinal Nephew damaged the papacy further when Paul was forced to remove him from office following a scandal. He curbed many clerical abuses in Rome but his methods were seen as harsh.