Pope Pius IV (1499-1565)

The Council of Trent, convoked by Paul III in 1545, had until 1559 led a chaotic existence. Its first two periods (1545-1547, then 1551-1552) had produced capital decrees, but the council had been suspended, transferred, paralyzed by the wars between Charles V and France, then abandoned. Julius III had reopened it without being able to finish it; Marcellus II had reigned only twenty-two days; and Paul IV, hostile to the very idea of a council that he considered dangerous to papal authority, had preferred reform by means of the Inquisition.^[7][8]

When Pius IV was elected at the end of 1559, Catholic Europe had for years been demanding the resumption and conclusion of the council. Protestantism had continued to gain ground; France was sliding toward the Wars of Religion; the Emperor and the king of Spain pressed Rome to act. The new pope understood that the future of the Church was at stake, and he made the decision that his predecessors had avoided or feared: to convoke a third and final period of the council and lead it to completion, whatever the cost.^[9][10]

“Pius IV devoted his undivided attention to the completion of the labours of the Council of Trent.” — The Catholic Encyclopedia, “Pope Pius IV”^[11]

This is what makes him a less spectacular but profoundly effective pope. He did not invent Trent; he saved it. Without his diplomatic persistence between 1560 and 1563, the great council of the Catholic Reform might have remained an abandoned worksite, and the Church would have entered the following centuries without the doctrinal and disciplinary charter that would structure her until Vatican II. The details of the Tridentine decrees belong to the article devoted to the council; what belongs properly to Pius IV is that he brought it to victory.

Before becoming the pope who completed Trent, Giovanni Angelo Medici was a man who began very low, owing everything to his legal intelligence, patience, and the military fortune of a feared brother. Nothing in his origins destined him for the tiara.

A modest Milanese family

Giovanni Angelo Medici was born on 31 March 1499 in Milan, the second child of a large family of humble condition.^[12][13] His father, Bernardino Medici, was a tax farmer, a collector rather than a lord. The family belonged to a Milanese branch of the Medici that claimed kinship with the great Florentine house of the Medici, but modern historians have found no proof of that link.^[14] The future pope therefore owed nothing to a great name: he owed everything to work.

“He was of humble extraction; his father was a tax farmer.” — The Catholic Encyclopedia, “Pope Pius IV”^[15]

The shadow of a condottiere brother: Gian Giacomo Medici

The rise of the family first depended on one man: Giovanni Angelo's elder brother, Gian Giacomo Medici, nicknamed il Medeghino. A brutal and skillful soldier of fortune, he carved out a principality around Lake Como, entered the service of the Emperor Charles V, and received from him the title of marquis of Marignano.^[16][17] Commander of imperial troops, he distinguished himself especially in the conquest of Siena (1555). It was this brother's military fame that opened the doors of the Roman career to the younger son: in sixteenth-century Italy, a name carried by arms was a recommendation.

The jurist: Pavia, Bologna, and the doctorate of 1525

Giovanni Angelo first studied philosophy and medicine at Pavia, then law at Bologna, where on 11 May 1525 he obtained a doctorate in civil and canon law.^[18] This legal training is the key to his whole destiny: it made him a competent administrator and precise negotiator, qualities that mattered more than devotion in a Curia that also governed states. At twenty-eight, he entered the service of the Church and arrived in Rome on 26 December 1527 — nearly thirty-two years before his election to the supreme pontificate, almost to the day.^[19]

The curial career: from Clement VII to the purple (1549)

In Rome, his rise was slow but steady. Clement VII made him apostolic protonotary. Under Paul III, he governed several cities of the Papal States, proving himself a firm and effective administrator.^[20] Rewarded for his service, he was named archbishop of Ragusa (today Dubrovnik) in 1545, then created cardinal-priest of Santa Pudenziana on 8 April 1549, in the last year of Paul III's pontificate.^[21][22]

The reign of Paul IV (1555-1559), however, brought an eclipse: the austere and suspicious Carafa pope distrusted this too-flexible, too-worldly cardinal and kept him at a distance. That exclusion paradoxically prepared his election: when the Church, weary of Paul IV's harshness, looked for a man of appeasement, Medici's name imposed itself precisely because he had been the opposite of the deceased pontiff.^[23][24]

At Paul IV's death on 18 August 1559, one of the longest and most contested conclaves of the century began. For nearly four months, the Sacred College remained blocked by the rivalry of two great parties: the French faction and the Spanish-imperial faction, each refusing the other's candidate.^[25][26] No name reached the required majority; pressure from the crowns paralyzed the ballots.

It was the skill of Cardinal Alessandro Farnese, grandson of Paul III, that finally broke the deadlock by gathering the undecided around Giovanni Angelo Medici, a compromise candidate acceptable to all because he was not bound to any one party.^[27] Elected by acclamation on Christmas night, 25 December 1559, he took the name Pius IV and was crowned on 6 January 1560, the feast of the Epiphany.^[28][29]

“The conclave lasted over three months, the French and Spanish-Austrian parties neutralizing each other. The efforts of Cardinal Farnese at last secured Medici's election by acclamation.” — The Catholic Encyclopedia, “Pope Pius IV”^[30]

The choice reveals what the Church expected. After the intransigence of Paul IV, Catholics wanted a conciliatory, legal-minded pope capable of negotiation rather than fulmination. Pius IV would fulfill that program — for the better, by saving the council; and, at first, for the harsher, by settling accounts with the family of the dead pope.

The first major act of the pontificate was not a reform but a judicial revenge. Under Paul IV, his Carafa nephews had exercised scandalous power, mixing nepotism, violence, and intrigue, until the old pope himself disgraced them in 1559. Pius IV decided to bring them to trial.

A sensational trial (1560-1561)

Paul IV's nephews and close associates were arrested and tried for a series of crimes — murders, abuses of power, and embezzlement.^[31][32] The trial, conducted with implacable severity, ended on 6 March 1561: Cardinal Carlo Carafa was strangled in his prison in Castel Sant'Angelo, and his brother Giovanni Carafa, duke of Paliano, was beheaded with his closest associates.^[33][34] For Pius IV, striking the family of the preceding pope was at once an act of justice, a demonstration of authority, and a warning to the Curia.

A justice later disavowed

Historical judgment has remained divided. Some of the Carafa crimes were real, but the procedure and the severity of the sentence seemed excessive and politically interested to many observers. The proof is striking: his successor Saint Pius V, a reforming pope and a man of moral rigor, rehabilitated the Carafa and declared their condemnations unjust.^[35] This episode shows that Pius IV's firmness could turn into harshness when his own interest and that of papal authority were at stake — a nuance Catholic historiography does not hide.

If nepotism was Pius IV's defect, in his case it took a providential turn. The nephew he raised was not a dissipated prince, but one of the greatest reforming saints in the history of the Church.

A twenty-one-year-old cardinal-nephew

On 31 January 1560, barely elected, Pius IV created his nephew Charles Borromeo, son of his sister Margherita, twenty-one years old, a cardinal and entrusted to him the office of Secretary of State.^[36][37] The appointment first belonged to ordinary nepotism: family was placed in key offices. But the young man would transform that favor into heroic service of the Church.

“Pius IV was luckier than his predecessors in the youth whom he created cardinal-nephew: Charles Borromeo, the glory of Milan and of the Universal Church in the sixteenth century.” — The Catholic Encyclopedia, “Pope Pius IV”^[38]

The driving force behind the conclusion of Trent

Borromeo became the true administrative architect of the council's final period. Tireless, he pressed the pope, coordinated the legates, and maintained diplomatic pressure on the European courts so that the council would resume and conclude. The Catholic Encyclopedia notes that Pius IV found in him the man needed to carry this important work through and bring its decisions into the life of the Church.^[39] Without the laborious holiness of this nephew, Pius IV's pontificate would not have had its executive arm.

From the Curia to the archdiocese of Milan

After the council closed, Borromeo renounced curial life to become an exemplary resident archbishop in Milan, where he applied the decrees of Trent to the letter: seminaries, pastoral visits, catechism, discipline of the clergy. He became the model bishop of the Catholic Reform and was canonized in 1610. The irony is strong: Pius IV's nepotism, an abuse in principle, gave the Church one of her purest reformers. Borromeo's own biography belongs to a dedicated article; here, what matters is that he was the living instrument of his uncle's work.

The work that dominates the whole pontificate, and for which history remembers Pius IV, is the third and final period of the Council of Trent. Resuming a council suspended for ten years in a torn Europe was a diplomatic gamble.

The difficult convocation

From his election onward, Pius IV announced his intention to reopen the council.^[40] But the obstacles were immense: France, entering the Wars of Religion, was tempted by the idea of a national Gallican council; the Emperor Ferdinand I wanted concessions to Protestants (communion under both kinds, clerical marriage) in order to bring them back; Philip II's Spain intended to control everything. The pope had to maneuver among these contradictory demands without letting the council escape him or reopening the old quarrel of conciliarism — the thesis that a council is superior to the pope.^[41][42]

The reopening of 18 January 1562

At the cost of relentless diplomacy, the council solemnly reopened at Trent on 18 January 1562.^[43] The sessions then followed one another decisively, treating the most disputed questions that the earlier periods had left unresolved: communion under both kinds, the sacrifice of the Mass, the sacrament of Orders, marriage, purgatory, the cult of saints, relics, and images, indulgences, and above all a vast disciplinary reform — including the capital decree on founding seminaries in every diocese.^[44]

The closing of 4 December 1563

After overcoming serious crises — disagreements among nations, threats of departure by the French bishops, permanent tension with the Emperor and Spain — the council held its final sessions and closed solemnly on 4 December 1563.^[45] Eighteen years after it had been opened by Paul III, the great council of the Catholic Reform was at last completed. For Pius IV, it was the triumph of an entire reign.

“Pius IV had the satisfaction of seeing the close of the long-continued council and the triumph of the papacy over the anti-papal tendencies which had at times asserted themselves.” — The Catholic Encyclopedia, “Pope Pius IV”^[46]

The doctrinal content of these decrees — the definition of justification, the sacraments, and the Eucharistic sacrifice — belongs to the article on the Council of Trent and to the systematic refutation set out in the answers to Protestantism. What belongs to Pius IV is the political and spiritual feat of bringing this assembly to completion.

Completing the council was not enough: its authority had to be guaranteed and its application imposed. Pius IV devoted the last two years of his reign to a series of magisterial acts that made him the juridical guarantor of the Catholic Reform.

The bull Benedictus Deus (1564)

By the bull Benedictus Deus, subscribed on 26 January 1564 and published the following summer, Pius IV solemnly confirmed all the decrees of the Council of Trent and reserved every official interpretation to the Holy See alone, forbidding private commentaries that might alter their meaning.^[47][48] This act was capital: it transformed the decisions of an assembly into law for the universal Church, and it protected the council against any conciliarist or national appropriation.

“The decrees were confirmed on 26 January 1564 by Pius IV in the Bull Benedictus Deus, and accepted by the Catholic countries, by some with reservations.” — The Catholic Encyclopedia, “Pope Pius IV”^[49]

The Tridentine Profession of Faith (1564)

The council had not drafted its own symbol of faith. Pius IV entrusted a commission of cardinals with composing a synthetic formula summarizing the Catholic faith reaffirmed at Trent, in explicit opposition to Protestant theses. By the bull Iniunctum nobis of 13 November 1564 (completed by the constitution In sacrosancta beati Petri for universities), he made this Profession of Faith obligatory for every holder of ecclesiastical office, every bishop, and every candidate for a university degree.^[50][51]

“His name will ever be connected with the ‘Profession of Faith,’ which must be sworn by every holder of an ecclesiastical office.” — The Catholic Encyclopedia, “Pope Pius IV”^[52]

This text, long called the “Creed of Pius IV” or Professio fidei Tridentina, remained for centuries the oath of doctrinal fidelity of the Catholic clergy. It is one of the most durable legacies of the pontificate.

The Index, the Catechism, the Missal, and the Breviary

Pius IV also put into motion the instruments of application desired by the council. In 1564 he had a new Index of Forbidden Books published, the so-called Tridentine Index, accompanied by ten general rules on the censorship of writings dangerous to the faith.^[53][54] He launched the drafting of the Roman Catechism (the “Catechism of the Council of Trent”), as well as the reform of the Missal and Breviary, projects he would not live to see completed: they would be finished and promulgated by his successor Saint Pius V.^[55] Here again, Pius IV was the initiator of a work that others would complete, just as he himself had completed the work of Paul III.

The whole style of Pius IV contrasts with his predecessor's rigidity. A jurist rather than a mystic, a diplomat rather than a prophet, he governed by relaxation and appeasement — an orientation with both merits and limits.

The contrast with Paul IV

The table below summarizes the opposition of temperament and method between the two successive pontificates. It explains why the Church swung from one extreme to the other in 1559.

Easing the severity

Pius IV eased several measures inherited from Paul IV. He moderated the harshness of the Roman Inquisition, softened certain restrictions imposed on the Jews of Rome — allowing them, for example, to own property up to a certain value — and restored a calmer climate to the city after years of tension.^[56][57] This policy of de-escalation earned him real popularity, but also the reproach of softness from the most rigorous reformers.

Diplomacy in the service of unity

Most of Pius IV's energy went into negotiation with princes. To reopen and bring the council to completion, he had to handle the Emperor Ferdinand I, the king of Spain Philip II, and France; he had to bring each party back to the table without yielding on doctrinal essentials. This diplomatic patience, so different from Paul IV's anathemas, was the very condition for Trent's success: an intransigent pope would have driven the nations away; a flexible pope kept them there until the end.^[58][59]

Like all the great popes of the late Renaissance, Pius IV was a builder. His reign left major monuments in Rome, where the genius of Michelangelo came again into the service of the papacy.

Porta Pia, Via Pia, and urban planning

Pius IV opened a great straight artery, the Via Pia (today's Via XX Settembre), and marked its entrance with the famous Porta Pia, one of the last architectural works of Michelangelo (begun in 1561).^[60] This act of urban planning inscribed his name into the fabric of the city itself and extended the great tradition of papal patronage opened by Julius II and Paul III.

Santa Maria degli Angeli and the Casina Pio IV

The pope also entrusted Michelangelo with transforming the immense Baths of Diocletian into a basilica, Santa Maria degli Angeli e dei Martiri, a highly symbolic act by which a pagan monument was consecrated to Christian worship. In the Vatican gardens, he had the delicate Casina Pio IV built, a pleasure pavilion of refined Mannerist elegance.^[61] He also restored the Roman university (the Sapienza), founded a papal printing press, and improved the city's water supply.^[62]

The reverse side: a costly reign

This policy of prestige and the war against the Turks in Hungary weighed heavily on finances. Pius IV had to impose heavy taxes, which chroniclers reproached him for.^[63] The monumental grandeur of the reign had its price, and the generosity of the builder was paid for by fiscal severity — a familiar contradiction in the whole history of papal patronage.

The final years of the pontificate were marked by a dramatic episode: an assassination attempt. In 1565, an enthusiast named Benedetto Accolti, at the head of a small group of mystical conspirators convinced they were acting under supernatural inspiration, planned to kill the pope.^[64][65] The plot, apocalyptic in tone, was uncovered in time; Accolti and his accomplices were arrested and executed. The strange affair reveals the religious fever of the age, when zealots could believe that murdering a pope was a divine mission.

Weakened by the gout that had been consuming his limbs for years and forced him to be carried in a chair, Pius IV declined rapidly. Struck by Roman fever, he died in Rome on 9 December 1565, at sixty-six, assisted by two saints: his nephew Saint Charles Borromeo and Saint Philip Neri, the apostle of Rome.^[66][67] This death surrounded by sanctity sums up the paradox of the man better than any speech: a pope of government, neither mystical nor heroic, but whom Providence had placed at the crossroads of the saints who were refounding the Church.

A tomb at Santa Maria degli Angeli

First buried at Saint Peter's, Pius IV's body was transferred in 1583 to the basilica he had caused to be built, Santa Maria degli Angeli, where his tomb stands.^[68] He thus rests in the very monument that symbolizes his reign: a Christian sanctuary drawn out of the ruins of imperial Rome, like a Church rising again from the ruins of division.

The verdict of history

How should Pius IV be judged? Historiography, including Catholic historiography, remembers an uneven but decisive pontiff. On the personal level, his reign bears the mark of nepotism and the stain of the Carafa trial, later annulled. On the institutional level, he was the pope who completed the greatest work of Catholic modernity: without his diplomatic persistence, the Council of Trent might have remained unfinished.^[69][70]

The annalist Ludovico Antonio Muratori fixed the memory the Church keeps of him: his name would remain “in benediction for having brought to a glorious termination the Council of Trent,” for having reformed tribunals, maintained order, and promoted worthy cardinals.^[71][72] His dream of recovering Protestant Germany by conciliation died with him; but the doctrinal edifice he sealed would stand for four centuries.^[73]

Pius IV thus illustrates a deep law of Church history: God completes through some what he began through others. Paul III had convoked Trent; Pius IV closed it; Saint Pius V would apply its decrees with burning holiness. Between the reforming prince and the austere saint, the Milanese jurist was the patient worker who linked the two — and it is precisely this patience, more than brilliance, that makes his greatness.

• The Council of Trent (1545-1563) — the dogmatic work reopened and completed by Pius IV; the detail of its decrees.
• Pope Paul III (1468-1549) — the pope who convoked the council that Pius IV would bring to completion.
• Pope Paul IV and Marcellus II — the immediate predecessors whose severity Pius IV reversed.
• Pope Julius III — who had reopened the second period of the council without being able to finish it.
• Pope Saint Pius V — his successor, who applied Trent's decrees and completed the Catechism, Missal, and Breviary.
• Saint Charles Borromeo — his cardinal-nephew, driving force of reform and model Tridentine bishop.
• The Catholic Reform (Counter-Reformation) — the great movement of which Trent was the charter.
• The Catholic answers to Protestantism — the doctrinal refutation elaborated from the Tridentine decrees.