What similarities and differences exist between the two unions—the Florence and the Brest? How relevant are these two attempts to unite Orthodox and Catholics for Ukraine today? What role did the Kyiv Church play in the Florence and Brest Councils? These questions form the foundation of this brief historical essay.
What Unites and What Divides: The Florence and Brest Unions
Ἵνα πάντες ἓν ὦσιν—ut unum sint—"that they all may be one!" These words from the Gospel of John (17:21) are frequently heard at ecumenical conferences, cited in numerous articles, and used as epigraphs for published sermons, reflections, and books. Yet, over time, the sharpness of Christ's plea can begin to fade; ears grow accustomed, and hearts stop responding. However, these words encapsulate the Church's mission throughout its history. Even the call to “make disciples of all nations” has not stood as the Church's ultimate slogan—missions begin and end, nations embrace or reject the Good News of salvation, but the longing and quest for unity remain an unfulfilled ideal and a sacred commandment from the Savior. A commandment that His disciples broke within the first decades of the Church’s existence—an ideal no disciple of His, for whom the Teacher’s words hold any value, can avoid.
As harrowing as the stories of division and disputes between churches and Christians may be, equally vivid and noble are the attempts to overcome schisms and restore the lost unity of God's assembly. The year 1054, marked by blood and darkness, saw the final rupture between Constantinople and Rome—the culmination of centuries of disagreements throughout the first millennium. Yet, 1439 and 1596 shine with golden and heavenly hues, as these were the glorious years when Christians of the East and West once again restored Eucharistic communion, becoming truly one Church as proclaimed in the Creed. The one, holy, catholic, and apostolic Church rejoiced in this unity—although, tragically, both times, only for a short while.
The Council of Ferrara-Florence (1438–1445)
Discussions about convening a unifying ecumenical council between Catholics and Orthodox had been ongoing for centuries before the Florence Union. For instance, Barlaam of Calabria, known for his polemics with Gregory Palamas, urged Pope Benedict XII to initiate such a council in 1339. Similarly, Byzantine Emperor John VI Kantakouzenos formally proposed the idea to Rome in 1350.[1] While Rome responded favorably to these proposals, it was reluctant to reopen doctrinal debates, citing the earlier Union of Lyons and regarding the Second Council of Lyons (1274) as ecumenical and its decisions as valid. However, by the late 1430s, both sides were prepared for dialogue, and the council was convened in Ferrara in 1438.
The climax of the Council of Ferrara-Florence, regarded by Orthodox participants of the time as the Eighth Ecumenical Council and by Catholics as the Seventeenth, was the signing of the union in 1439. This document restored unity between the churches of the Byzantine tradition, led by Constantinople, and the Western Church, represented by Rome. A distinctive feature of this council was that the primary catalyst for Eastern Christians’ pursuit of unity was the looming threat of Turkish invasion, prompting Constantinople to seek support from the Latin West. Emperor John VIII Palaiologos played a significant role in persuading Eastern bishops to embrace the union.[2] However, reducing the motivations behind the union solely to political considerations would be oversimplistic. A number of influential Orthodox figures of the time sought unity with the Catholic Church, including Patriarch Joseph II of Constantinople, the prominent Metropolitan Isidore of Kyiv, and—of particular significance to us—a bishop from Suzdal, whose signature is also found on the final union document. This active participation of representatives of the Kyiv Church underscores the longstanding quest for unity that characterized Christians of Rus’ following the break in communion between Rome and Constantinople in the mid-11th century.
Another notable aspect of the Florence Council was the resolution of major theological disputes that had arisen between Orthodox and Catholics over centuries, starting from the so-called Photian Schism (late 9th century). During the council sessions, leading theologians from both East and West debated topics such as the procession of the Holy Spirit (Filioque), the use of leavened versus unleavened bread in the Eucharist, fasting practices, the primacy of the Roman See in the Universal Church, and many other contentious issues. Consensus was reached on all these matters. However, as subsequent history revealed, not all Eastern representatives were sincere in their agreement—within a few years of the council, some signatories rejected the union and declared their previous decisions erroneous. Nevertheless, the Florence Union became a key motivating factor for theologians and hierarchs of the Kyiv Metropolia to later explore ways to restore communion with the Roman pontiff.
In conclusion, the Florence Council did not achieve lasting unity between Catholics and Orthodox. Political circumstances and a lack of consensus within local Orthodox Churches led to the renewal and deepening of the schism.
The Brest Council of the Ruthenian Church (1596)
The fate of the Brest Council was markedly different from that of the Council of Ferrara-Florence. Unlike the latter, the Brest Council was not ecumenical but rather a local council of the Kyiv Metropolia within the Patriarchate of Constantinople. The jurisdiction of this metropolia encompassed much of modern-day Ukraine, Lithuania, and Belarus.
Since the schism, Christians in Kyiv were caught in the political maneuvering of more influential ecclesiastical centers. For a century, the split between Rome and Constantinople was not perceived as a formal division of the Church in Rus’. Even after the schism, Rus’ continued to host delegations from the Roman Church, celebrate certain Latin feasts, and officiate inter-ritual marriages without hesitation.[3] Even after the Orthodox patriarchates rejected the decisions of the Florence Council, Kyiv Metropolitan Misail expressed, in a conciliar memorial of 1476, a vision of relations with the Roman Church as a sister Church to Constantinople and urged his episcopal brethren to restore communion with both patriarchates. This approach has led scholars to call Misail a “forerunner of the unionist aspirations of the Ruthenians.”[4]
By the late 16th century, the entire episcopate of the Kyiv Metropolia sought reunion with Rome. Evidence of this desire can be found in the Declaration of four bishops of the Kyiv Metropolia expressing readiness to accept union with Rome (1590), as well as in the Declaration of Metropolitan Mykhailo Rahoza and the episcopate of the Ruthenian Church (1594). The motives for this union included safeguarding the Kyiv Church against heresies spreading from Protestant Europe, addressing the crisis caused by spiritual decline and clerical ignorance,[5] and protecting Ruthenian churches, rites, and customs from efforts at Latinization by the Polish state-church authorities. These ideas and motivations were most comprehensively outlined in 33 articles[6] (1595), which formed the program for implementing the Brest Union the following year. Unfortunately, the post-Reformation Roman Church did not fully acknowledge these articles, and they were not mentioned in the papal union document Magnus Dominus et laudabilis nimis.
Simultaneously with the unionist council in Brest, an anti-unionist council was held, attended by two bishops of the Kyiv Metropolia and two bishops from other Orthodox jurisdictions. In their conciliar decree, they announced the deposition of the bishops who accepted the union, citing “apostasy from the Eastern Church.” Following this council—and especially after the Jerusalem Patriarch consecrated a new non-unionist hierarchy in 1620—the conflict escalated to the level of grassroots clergy and monastic orders. As a result, the Kyiv Church endured the drama of division for centuries, a struggle that continues to this day.
Similarities and Differences Between the Two Councils
The Florence and Brest Councils share several key features. Both aimed to overcome the schism, reflecting a sincere desire for unity by most hierarchs on both sides. Both councils were also influenced by political factors and later faced rejection by Orthodox patriarchates—either immediately or shortly after their conclusions.
However, the scale and outcomes of the councils differ significantly. The Florence Council was ecumenical by all standards, while the Brest Council was a local synod. The former failed to establish long-term unity, whereas the latter resulted in the formation and growth of the Unionist Christians of the Ruthenian-Byzantine tradition. These Unionists, by their very existence, continue to challenge the divided state of the apostolic Churches of the East and West. According to historian Yuriy Fedoriv, Florence had more politics, while Brest had more love; thus, the former failed to produce results, whereas the latter solidified unity for centuries:
"It would have been better if the motives for resolving ecclesiastical disputes and schisms were less secular and more spiritual; then even the Florence Council, which aimed to heal the wounds of Christ's Church, might have yielded better and more lasting results."[7]
In Florence, the Latin Church interacted with the Eastern patriarchates as equals, acknowledging them as sister Churches. By contrast, Brest reflected a post-Tridentine ecclesiology, which recognized only one true Church of Christ—the Roman Catholic Church. Under this framework, all other Christian communities, regardless of their prior dignity, were seen as needing to return to the Church through repentance and submission to the Pope’s direct jurisdiction.
These two councils—two attempts to restore unity—offer modern Christians much to ponder. While the Orthodox-Catholic Balamand Agreement [8] declared uniatism a flawed path to unity, the Florence and Brest Councils remind us that fulfilling Christ’s command for unity is both possible and necessary, even when it seems unattainable. Yet, only the action of the Holy Spirit can make the fruits of such endeavors lasting and transformative.
References
- Дж. Ґілл. Флорентійський собор. Львів, 2016, с. 24–25.
- The role of Byzantine emperors in convening Ecumenical Councils was always decisive for the Orthodox Church. Moreover, without imperial initiative, the early councils would have been impossible, as they required substantial financial support for organization and political backing for implementing conciliar decisions within the empire. Unfortunately, the motives of these rulers often strayed from spiritual concerns and were driven by a desire to maintain peace and order in the state, sometimes at the cost of orthodoxy.
- В. Гринєвич. Минуле залишити Богові. Львів, 1998, с. 17.
- Ibid., p. 51.
- “The corruption of the higher hierarchy was accompanied by ignorance and moral decline among parish priests and monks.” Борис Ґудзяк. Криза і реформа: Київська митрополія, Царгородський патріархат і ґенеза Берестейської унії. Львів, 2000, с. 86.
- Основні документи Берестейської унії. Львів, 1996, с. 54–61.
- Ю. Федорів. Історія Церкви в Україні. Львів, 2001, с. 148.
- The Balamand Agreement (1993) is not binding for either Catholics or Orthodox but contains important declarations reflecting the contemporary state of Orthodox-Catholic views on unity.