Pope Eugene IV (1431-1447)

The Pope of the Council of Florence

Eugene IV is above all the pope of the Council of Ferrara-Florence (1438–1445), the seventeenth ecumenical council of the Church according to the Latin reckoning (the Catholic count of the ecumenical councils). It was under his authority that the reunion of the Eastern and Western Christians was achieved, nearly four centuries after the schism of 1054. The union did not survive the fall of Constantinople (1453), but the dogmatic decrees it produced — on the procession of the Holy Spirit, purgatory, the Eucharist, and especially papal primacy — have remained established; the definition of primacy was reaffirmed by the First Vatican Council in 1870 (Pastor aeternus).^[10][11]

The Pope Who Defeated Conciliarism

Eugene IV’s pontificate marks the decisive turning point in the conflict between the pope and councils. The conciliarist movement, born from the need to end the Western Schism, claimed that supreme authority in the Church resided not in the pope but in the general council. The Council of Basel took this thesis to its extreme. By securing the union of the Greeks in his Council of Florence — and not at Basel — Eugene IV shattered Basel’s claim and triumphed for Roman primacy in the public forum of Christendom. The Basel assembly never recovered; but conciliarist theses outlived it — the conciliabule of Pisa would still attempt to suspend a pope in 1511, and Lateran V had to condemn it (2nd session, 17 May 1512).^[12][13][14]

The Pope of Union with the Eastern Churches

In six years, Eugene IV sealed union with the Greeks (1439), the Armenians (1439), the Copts and the Ethiopians (1442), the Syrians (1444), the Chaldeans (Nestorians) and the Maronites of Cyprus (bull of union of 7 August 1445).^[15] These unions, fragile in practice, remain in the Church’s memory as a high point of dogmatic ecumenism: not a compromise diluting the faith, but a common profession of the Catholic faith received by Churches of different rites.^[16][17]

The table below summarizes the Eastern Churches reunited with Rome at the Council of Florence, with the corresponding act of union and its main subject.

Our knowledge of Eugenius IV is based on a range of contemporary sources and modern scholarship. The acts of the Council of Florence — notably edited in the major collection of ecumenical councils by Norman P. Tanner — provide the exact text of the union bulls, with Laetentur caeli foremost.^[19] Humanist biographies, especially the Commentario della vita di Eugenio IV by the Florentine bookseller Vespasiano da Bisticci, a witness to the Florentine exile, offer the most vivid portrait of the man.^[20]

For the Basel crisis, the reference work remains the monograph by Joachim W. Stieber, Pope Eugenius IV, the Council of Basel and the Secular and Ecclesiastical Authorities in the Empire (Leiden, Brill, 1978), an exhaustive study of the power struggle between the pope, the council, and the princes.^[21] The older scholarly synthesis by James Loughlin in the Catholic Encyclopedia (1909) remains a solid foundation for the overall biography.^[22]

A Patrician Family and the Connection to Gregory XII

The future Eugenius IV was born in Venice around 1383, into a wealthy family of the merchant patriciate, son of Angelo Condulmer and Bariola Correr.^[23] This maternal lineage was decisive: his mother was the sister of Angelo Correr, who would become Pope Gregory XII (1406–1415), one of the key figures of the Western Schism. The young Gabriele was thus the nephew of a pope, and it was this uncle who launched his ecclesiastical career. Heir to a great fortune, he is said to have distributed 20,000 ducats to the poor before embracing religious life.^[24]

San Giorgio in Alga: The Canon Regular

Far from the worldly career his birth might have promised, Gabriele Condulmer entered religious life at a young age. Around 1400, he took part in founding a community of canons regular devoted to poverty and observance on the islet of San Giorgio in Alga in the Venetian lagoon, approved by the Holy See in 1404.^[25] This monastic imprint never left him: as pope, beneath the purple and the tiara, he retained the austere habits of his youth — a trait that illuminates both his piety and his rigidity.

Bishop of Siena, then Cardinal

The protection of his uncle Gregory XII accelerated his rise. On 30 December 1407, barely twenty-four years old, Gabriele was appointed bishop of Siena; but opposition from the Sienese to a foreign prelate forced him to renounce the see the following year.^[26] On 9 May 1408, Gregory XII created him cardinal-priest of San Clemente. Under the next pontificate, Eugenius — then cardinal — served as legate in the March of Ancona (Picenum) from 1420, then in Bologna from 1423; Martin V transferred him to the title of Santa Maria in Trastevere in 1427. When Martin V died, Cardinal Condulmer was an experienced prelate, seasoned in governing the Papal States.^[27][28]

The Conclave and the Electoral Capitulation

At the death of Martin V (the pope who had ended the Western Schism), the conclave opened on 1 March 1431 and, by 3 March, unanimously elected Cardinal Condulmer, who took the name Eugenius IV; he was crowned on the steps of Saint Peter’s on 11 March 1431.^[29] As was customary at a time when conciliarism weighed heavily on all minds, the cardinals had made the future pope swear an electoral capitulation committing him to share the governance of the Church and to respect the forthcoming council — a promise that would weigh heavily in what followed.^[30]

The War Against the Colonna

The new pope’s first act was a grave mistake with far-reaching consequences. Driven by a hatred of nepotism that his predecessor had pushed to extremes, Eugenius IV turned abruptly against the powerful Colonna family, from which Martin V had come and which he had showered with lands and fortresses. The repression escalated into open war in the Papal States. Supported by Florence, Venice, and Naples, the pope eventually prevailed: the Colonna surrendered their castles and paid an indemnity of 75,000 ducats.^[31] But this enmity, coupled with the ongoing unrest in Rome, set the stage for the revolt that would drive him from his capital three years later.

The Conciliarist Dream and the Decree Haec sancta

To understand the drama, one must go back to the Council of Constance (1414–1418), which ended the schism by deposing the rival claimants. In its famous decree Haec sancta (1415), Constance affirmed that the general council derives its power immediately from Christ and that all, including the pope, owe it obedience in matters of faith, the eradication of schism, and reform.^[32] The decree Frequens further provided for the regular convocation of councils. It was on this basis that the Council of Basel was convened in 1431, opened on July 23 by the representatives of the legate Giuliano Cesarini — John of Palomar and John of Ragusa —, the legate himself arriving at Basel only in September.^[33]

“This holy synod, legitimately assembled in the Holy Spirit, forming a general council and representing the Catholic Church militant, holds its power immediately from Christ; and whoever, of whatever state or dignity he may be, even if it be the pontifical dignity, is bound to obey it in matters concerning the faith, the eradication of schism, and the reform of the Church.” — Decree Haec sancta, Council of Constance, April 6, 1415^[34]

This doctrine — which the Catholic Church would later consider erroneous in its claim to permanently subordinate the pope to the council — was the time bomb that Basel was about to detonate.

The Bull of Dissolution (December 18, 1431) and the Retreat of 1433

Worried that Basel, initially poorly attended, was drifting toward dissent, Eugene IV made a major tactical error: by a bull dated December 18, 1431, he dissolved the council and summoned it to Bologna, closer to Rome.^[35][36] Instead of obeying, the Fathers of Basel refused to disperse, solemnly reaffirmed the superiority of the council over the pope (February 15, 1432), and gained the support of Emperor Sigismund and many princes. Isolated and militarily weakened, Eugene IV was forced to capitulate: by the bull Dudum sacrum (December 15, 1433), he recognized Basel as a legitimate ecumenical council since its opening.^[37][38] The papacy seemed then to be on its knees.

The Schismatic Council and Antipope Felix V

The truce did not last. When the crucial question of the place of union with the Greeks arose, the conflict flared again: the Greeks wanted an Italian city, the pope also; Basel stubbornly insisted on Avignon or Basel. Eugene IV decided: by the bull Doctoris gentium (September 18, 1437), he transferred the council to Ferrara.^[39] The radical majority remaining at Basel then took the step into schism: they suspended the pope (1438), then deposed him as a heretic on June 25, 1439, and elected on November 5, 1439 Duke Amadeus VIII of Savoy, a widower retired to the hermitage of Ripaille, as Felix V.^[40] He would be the last antipope in history. But Christendom, wary from a barely healed schism, largely disavowed Basel; Felix V would eventually submit in 1449 to Nicholas V. Eugene IV’s cause was saved — and the Basel assembly, broken.^[41][42]

A City in Revolt

Rome in the 15th century remained a turbulent and unruly city. Stirred up by the Colonna family, by Milanese intrigues, and by resentment against a Venetian and authoritarian pope, the population rose up in the spring of 1434 and proclaimed a short-lived Roman Republic. The pope found himself besieged in his own city.^[43]

The Pope Disguised as a Monk on the Tiber

This scene is one of the most striking in the entire history of the papacy. On June 4, 1434, Eugene IV, disguised as a simple monk, escaped the Vatican and descended the Tiber in a boat, amid a hail of stones thrown from both banks by the insurgents. He reached Ostia, then Pisa (June 12), and finally arrived in Florence, where he took up residence at the Dominican convent of Santa Maria Novella.^[44][45] The successor of Peter, driven out of Rome, would govern the Church for about nine years from exile.

Florence, Capital of Christendom

Far from being sterile, this exile made Florence the capital of Christendom. The city of the Medici, a center of humanism and the arts, hosted the papal court at the very moment when the first Renaissance was flourishing. It was there that Eugene IV forged ties with the great artists of the time and prepared the council of union.

The Consecration of Santa Maria del Fiore (1436)

On March 25, 1436, the Feast of the Annunciation and the first day of the year according to the Florentine calendar, Eugene IV solemnly consecrated the cathedral of Santa Maria del Fiore, recently crowned by Filippo Brunelleschi’s dome — a vast octagonal dome built without wooden centering, a feat the Opera di Santa Maria del Fiore presents as the largest masonry vault in the world.^[46] For the ceremony, the composer Guillaume Dufay wrote the motet Nuper rosarum flores, a pinnacle of polyphony. This act made Eugene IV, almost despite himself, a participant in the artistic spring of the West.

Why the Union? The Turkish Threat to Constantinople

The union of the Greeks was not primarily a matter of theological debate in an academic setting: it was a matter of survival. The Byzantine Empire, reduced to Constantinople and a few remnants, was surrounded by the Ottomans. Emperor John VIII Palaiologos knew that only the West could send a crusading relief force, and that this aid came at a price: religious reunion with Rome. Thus, it was a desperate emperor, accompanied by Patriarch Joseph II and nearly seven hundred Greeks, who arrived in Italy to negotiate.^[47]

Ferrara 1438, Florence 1439

The council opened in Ferrara on January 8, 1438 through Cardinal Albergati, even before the arrival of the Greeks; Eugene IV made his entry on January 27, and the Byzantine delegation, landed at Venice in February, reached Ferrara only in March.^[48] The theological debates between Latins and Greeks—on the Filioque, purgatory, the Eucharistic bread, and primacy—lasted over a year, intense and scholarly. The plague and lack of funds forced the pope to move the assembly to Florence in January 1439, at the expense of the Medici.^[49] It was there, after months of discussions in which Bessarion, Metropolitan of Nicaea, and Isidore of Kiev advocated for union, that agreement was finally reached.

“Laetentur caeli”: The Four Points of the Union (July 6, 1439)

On July 6, 1439, in the cathedral of Florence, the union bull Laetentur caeli—“Let the heavens rejoice”—was solemnly promulgated.^[50][51] It declared that the wall of separation between the Eastern and Western Churches had been torn down.

“Let the heavens rejoice and let the earth be glad! For the wall that separated the Church of the West and the Church of the East has been broken down; peace and concord have returned.” — Bull Laetentur caeli, Council of Florence, July 6, 1439^[52]

The decree settled the four points of contention: the procession of the Holy Spirit from the Father and the Son (the Filioque, recognized as compatible with the Greek “through the Son”); the reality of purgatory and prayers for the dead; the validity of the Eucharist with unleavened (yeast-free) or leavened bread according to the rites; and above all the primacy of the Roman pontiff. On this last point, Laetentur caeli solemnly defined primacy—a text whose substance the Vatican Council reaffirmed in 1870 (Pastor aeternus):

“We define that the Apostolic See and the Roman Pontiff hold primacy over the whole world; that the Roman Pontiff himself is the successor of the blessed Peter, prince of the Apostles, the true vicar of Christ, the head of the whole Church, the father and teacher of all Christians; and that to him, in the person of the blessed Peter, full power has been transmitted by our Lord Jesus Christ to feed, rule, and govern the universal Church, as is also contained in the acts of the ecumenical councils and in the sacred canons.” — Bull Laetentur caeli, July 6, 1439^[53]

The bull was signed by Emperor John VIII Palaiologos, the Greek bishops, and the Latins, led by Cardinal Cesarini. Patriarch Joseph II, however, had died in Florence a few weeks earlier, on June 10, 1439, after reportedly leaving a written profession of adherence to the Roman faith.^[54]

Mark of Ephesus, the Refusal of the Union

Only one Greek bishop obstinately refused to sign: Mark Eugenikos, Metropolitan of Ephesus, a strict theologian who considered the union a betrayal of Orthodoxy, especially regarding the Filioque.^[55] Upon his return to the East, his refusal became the banner of the rejection of the union. The resistance of monks, clergy, and the Greek people, who saw the union as capitulation, drained the agreement of its substance long before the fall of Constantinople erased it. The union of Florence was a doctrinal summit but a pastoral failure in the East—the history would show that Churches are not reunited by imperial decree.

Other Unions: Armenians, Copts, Nestorians

The council did not stop with the Greeks. Eugene IV also sealed union with the Armenians by the decree Exsultate Deo (November 22, 1439), which detailed the seven sacraments; with the Copts and the Ethiopians by the bull Cantate Domino (February 4, 1442)^[56]; with the Jacobite Syrians — represented by Archbishop Abdala of Edessa, legate of Patriarch Ignatius — by the bull of union of 30 November 1444 (13th session, held at the Lateran)^[57]; and then with the Chaldeans (Nestorians) and the Maronites of Cyprus by the bull of union of 7 August 1445 (14th session, held at the Lateran).^[58] In six years, Rome thus extended its hand to a series of separated Eastern Churches.

The union bull with the Copts, Cantate Domino of February 4, 1442 — also handed to the Ethiopian delegates present in Florence — contains one of the strongest — and most debated — formulations in the entire history of councils: the affirmation that "outside the Church, there is no salvation" (extra Ecclesiam nulla salus).

“The holy Roman Church firmly believes, professes, and teaches that none of those who are outside the Catholic Church, not only pagans but also Jews, heretics, and schismatics, can become partakers of eternal life; but that they will go into the eternal fire prepared for the devil and his angels, unless before the end of their life they are joined to it.” — Bull Cantate Domino, Council of Florence, February 4, 1442^[59]

Read literally and out of context, this phrase seems absolutely harsh. But the Church has never understood it as a condemnation of every man externally separated from Rome without fault on his part. The axiom extra Ecclesiam nulla salus primarily targets those who, knowing the truth of the Catholic Church, would knowingly refuse to enter or remain in it.^[60] As early as the 19th century, Pius IX clarified that those who are in invincible ignorance of the true religion and live according to natural law can obtain salvation through divine grace, without contradicting the dogma.^[61] The Vatican II Council would develop this same doctrine in continuity, teaching that those who, through no fault of their own, are ignorant of the Gospel but seek God with a sincere heart may be saved.^[62]

There is therefore no rupture between Cantate Domino and the more recent teaching, but a consistent development: the necessity of the Church for salvation remains intact, while the Church clarifies how this necessity applies to those whom the grace of Christ touches by paths known only to God. Christ and His Church remain the sole source of salvation; no one is saved against the Church, but some may be saved through it without knowing it.^[63]

At the very heart of this Florentine exile, Eugene IV took an act of considerable moral significance, too often overlooked. Learning that European Christians were reducing the inhabitants of the Canary Islands — the Guanches — baptized or freely seeking baptism, to slavery, the pope promulgated at Florence, on January 13, 1435, the bull Sicut Dudum.^[64] He condemned the enslavement of these peoples and ordered, under penalty of automatic excommunication (latae sententiae), their release within fifteen days, without ransom.

“We order and command all and each of the faithful, within fifteen days after the publication of these letters in the place where they reside, to restore to their former liberty all and each, of both sexes, who were formerly inhabitants of the said Canary Islands and made captives since the time of their capture, and who have been reduced to slavery.” — Bull Sicut Dudum, Eugene IV, January 13, 1435^[65]

This act, more than fifty years before the mass Atlantic slave trade, was taken as soon as Rome had been informed: the bull itself (§ 1) says the pope has just learned the facts from Bishop Ferdinand of Rubicón, messengers of the islanders, and other trustworthy informants — “condemned as soon as discovered,” as Fr. Panzer summarizes.^[66] It is a disciplinary prescription backed by a penalty, latae sententiae excommunication, grounded in natural law, the faith received, and baptism: not a doctrinal definition, but a norm whose demand subsequent popes would reprise. It did not end the abuses: Portuguese raids continued in 1435, and King Duarte of Portugal, after his complaints, obtained a tempering by the bull Romanus Pontifex of 15 September 1436.^[67]

The Council, a Center of Humanism

Exile and the council made Eugenius IV, without his seeking it, a patron of the nascent Renaissance. The arrival of Greek scholars in Italy for the Council of Florence brought the West manuscripts and a direct knowledge of Greek that nourished humanism. The pope protected artists, and the Dominican painter Fra Angelico, whom he summoned to Rome, is associated with his Florentine and Roman circle.^[68]

The Triumphal Return of 1443

Patiently, through arms and diplomacy, Eugenius IV reconquered his States. After a treaty with Alfonso of Aragon, King of Naples (1443), he finally returned to his capital: on 28 September 1443, after about nine years of exile, he made a triumphal entry into Rome.^[69] Aged and ill, he devoted his last years to raising Rome from its sad state, in Loughlin’s words.^[70]

The Basel crisis left a wound: the neutrality observed by many German princes, who had recognized neither Eugenius nor Felix V. To bring Germany back to Roman obedience, the dying pope concluded on 5 and 7 February 1447 the Princes’ Concordat (or Concordat of Frankfurt), a series of four bulls by which he made significant concessions to the Empire. On the same day, aware that he had yielded under the pressure of illness, he issued a salvatorian bull (Bulla Salvatoria) clarifying that his concessions, made “in his last illness,” did not intend to compromise the rights of the Apostolic See.^[71] This was one of his last acts.

Exhausted by sixteen years of struggles, Eugenius IV died in Rome on 23 February 1447, a few days after signing the concordat. He was first buried in the basilica of Saint Peter, near the tomb of Eugenius III; his funerary monument was later transferred to the Roman church of San Salvatore in Lauro.^[72] Tradition holds that on the threshold of death, this Venetian patrician cast into the storm regretted ever having left the peace of his cloister at San Giorgio in Alga, believing he would have been happier remaining a simple canon than wearing the tiara.^[73] If authentic, the remark sums up an entire pontificate: that of a man of prayer crushed by the affairs of the world.

His successor, the scholar Tommaso Parentucelli, ascended the throne as Nicholas V — humanist, founder of the Vatican Library — and reaped the fruits of Eugenius IV’s victory over the Basel assembly.

How should this pontificate be judged? On a human level, the record seems heavy: a pope driven from Rome, deposed by a council, contested by princes. Eugenius IV’s lack of tact — to which Loughlin attributes a good share of his trials — alienated many supporters.^[74]

But it would be a mistake to stop there. For this tested pope won, on the very ground where he was expected to be defeated, two decisive victories. He broke the Basel assembly by securing the union of the Greeks at his council rather than at Basel, saving the Roman primacy that would be solemnly defined at Vatican I. And through the Council of Florence, he gave the Church dogmatic decrees of permanent authority on the Trinity, purgatory, the sacraments, and the papacy.^[75][76] Added to this were the brilliance of the ecumenical union with the East, the defense of the natives of the Canaries, and the involuntary patronage of the Renaissance.

History thus records a paradox: one of the most unhappy pontificates in its course was one of the most fruitful in its results. Eugenius IV did not reign as a triumphant ruler; but the Church, emerging from the conciliar crisis stronger than it had entered, owes him for having held, in the storm, the helm of Peter’s primacy.

• The Council of Constance (1414-1418) — the council that ended the Western Schism and whose decree Haec sancta established conciliarism, opposed by Eugene IV.
• The Western Schism — the crisis from which the papacy of Eugene IV emerged, and the context of conciliarism.
• The Eastern Schism (1054) — the rupture between Rome and Constantinople that the Council of Florence sought to heal.
• The Fall of Constantinople (1453) — the event that sealed the failure of the Union of Florence in the East.
• The Church and Slavery — the topic within which Eugene IV’s bull Sicut Dudum is situated.
• Responses to Orthodoxy — the doctrinal issues (Filioque, primacy, purgatory) debated at Florence.