Alessandro Farnese (cardinal) in the context of Alexander Farnese, Duke of Parma

Pope Paul IV (Latin: Paulus IV; Italian: Paolo IV; 28 June 1476 – 18 August 1559), born Gian Pietro Carafa, was head of the Catholic Church and ruler of the Papal States from 23 May 1555 to his death, in August 1559. While serving as papal nuncio in Spain, he developed an anti-Spanish outlook that later coloured his papacy. In response to an invasion of part of the Papal States by Spain during his papacy, he called for a French military intervention. After a defeat of the French and with Spanish troops at the edge of Rome, the Papacy and Spain reached a compromise: French and Spanish forces left the Papal States and the Pope thereafter adopted a neutral stance between France and Spain.

Carafa was appointed bishop of Chieti, but resigned in 1524 in order to found with Saint Cajetan the Congregation of Clerics Regular (Theatines). Recalled to Rome, and made Archbishop of Naples, he worked to re-organise the Inquisitorial system in response to the emerging Protestant movement in Europe, any dialogue with which he opposed (the inquisition itself had been first instituted by Pope Innocent III who first regulated inquisitional procedure in the 13th century). Carafa was elected pope in 1555 through the influence of Cardinal Alessandro Farnese in the face of opposition from Charles V, Holy Roman Emperor. His papacy was characterised by strong nationalism in reaction to the influence of Philip II of Spain and the Habsburgs. The appointment of Carlo Carafa as Cardinal Nephew damaged the papacy further, and scandals forced Paul to remove him from office. He curbed some clerical abuses in Rome, but his methods were seen as harsh. He would introduce the first modern Index Librorum Prohibitorum or "Index of Prohibited Books" banning works he saw as in error. In spite of his advanced age, he was a tireless worker and issued new decrees and regulations daily, unrelenting in his determination to keep Protestants and recently immigrated Marranos from gaining influence in the Papal States. Paul IV issued the Papal bull Cum nimis absurdum, which confined Jews in Rome to the neighbourhood claustro degli Ebrei ("enclosure of the Hebrews"), later known as the Roman Ghetto. He died highly unpopular, to the point that his family rushed his burial to make sure his body would not be desecrated by a popular uprising.

The House of Farnese (/fɑːrˈneɪzi, -zeɪ/, also US: /-eɪsi/, Italian: [farˈneːze, -eːse]) was an influential family in Renaissance Italy. The titles of Duke of Parma and Piacenza, Duke of Latera and Duke of Castro were held by various members of the family.

Its most important members included Pope Paul III, Alessandro Farnese (a cardinal), Alexander Farnese, Duke of Parma and Piacenza (a military commander and Governor of the Spanish Netherlands), and Elisabeth Farnese, who became Queen of Spain and whose legacy was brought to her Bourbon descendants.