Orthodox Communities and the Union of Brest

The Union of Brest brought part of the Orthodox hierarchy of the Polish-Lithuanian Commonwealth into communion with the pope in 1595–1596. Its supporters sought to retain their Eastern worship and church organization while changing the authority to which their bishops belonged. The result was an Eastern-rite Catholic church alongside continuing Orthodox communities, with rival claims to leadership and property in the same regions.

The communities involved lived mainly in Ruthenian lands associated with the heritage of medieval Rus’. These included territories of both the Polish Crown and the Grand Duchy of Lithuania, now lying in several modern countries. Bishops, nobles, clergy and lay organizations took different positions on the union and its consequences.

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Bishops, parishes and lay brotherhoods

Orthodox church life had developed in the Rus’ territories long before they entered Polish or Lithuanian rule. Parishes supplied worship and rites around birth, marriage and death. Monasteries supported religious communities and learning. Bishops governed eparchies, ecclesiastical districts, under a metropolitan, a senior bishop responsible for several districts. The metropolitanate associated with Kyiv maintained a relationship with the patriarch of Constantinople, a leading authority in Eastern Christianity.

Patronage connected church institutions to rulers and landowners. A noble could support a monastery, provide land or defend a school. Clergy and lay patrons could nevertheless disagree over appointments, property and religious policy. The resources behind a church created interests extending beyond the bishop alone.

Lay brotherhoods became particularly significant in cities such as Lviv and Vilnius. They supported schools, hospitals and people in need, and defended Orthodox teaching. Some received a special status placing them directly under the patriarch rather than the local bishop. This arrangement strengthened their ability to challenge episcopal conduct. It also alarmed bishops who wanted more secure control over their own districts.

Reform and the competing proposals for unity

The Reformation and Catholic reform placed Orthodox leaders within a wider contest over teaching, schools and church authority. Jesuits established themselves in Lithuania in 1569 and promoted Catholic education. Piotr Skarga’s book of 1577 argued for church unity under Rome, addressing the influential Orthodox patron Prince Konstanty Wasyl Ostrogski.

Patriarch Jeremias II visited the region in 1588–1589 and intervened in its church affairs. He replaced the metropolitan and strengthened some brotherhoods. Annual synods, assemblies of church leaders, discussed reform and the possibility of union. A declaration favouring union appeared in 1590, followed by further negotiation.

The participants did not share one design. Ostrogski favoured a wider agreement involving Eastern patriarchs and other Orthodox authorities, with improved education and preservation of tradition. Bishops supporting a regional settlement sought a more immediate arrangement between the Commonwealth’s metropolitanate and Rome. They also wanted stronger episcopal standing, protection of church property and a political position comparable to that of Latin Catholic bishops.

The journey to Rome and the Brest synods

In June 1595, the bishops prepared articles setting out conditions for union. Hypatius Pociej and Cyril Terlecki then travelled to Rome, where they made a profession of faith before Pope Clement VIII in December. Papal documents confirmed the reception and addressed the Ruthenian church’s rights and organization.

The agreement was proclaimed at Brest, in what is now western Belarus, in October 1596. Its opponents held a separate assembly in the city. Ostrogski supported resistance, and the bishops of Lviv and Przemyśl, Hedeon Balaban and Mykhailo Kopystenskyi, rejected the settlement. King Sigismund III Vasa supported the union, and its adherents could call on powerful political patrons.

These parallel gatherings revealed the central disagreement over authority. The supporting bishops claimed the right to lead their churches into communion with Rome. Opponents maintained their relationship with Constantinople and denied that the agreement bound the wider Orthodox community. Proclamation began a struggle over recognition.

What changing allegiance meant in worship

The churches accepting union acknowledged the pope’s authority while retaining an Eastern rite. A rite comprised the services, ceremonies and practices through which worship was conducted. The bishops’ proposed terms named morning and evening prayer services, their language of worship, baptism and the liturgy, the principal service centred on the Eucharist. In that Christian sacrament, worshippers received bread and wine understood as Christ’s body and blood. The bishops sought to retain communion in both forms. Preserving the rite concerned the activities performed in parish churches throughout the year.

They also sought to retain married priests and their established Easter observances. Calendar proposals addressed the date of Easter and feasts such as Theophany, which commemorated Christ’s baptism and included the blessing of water. These matters affected clergy’s households and the annual schedule of parish life.

The articles treated doctrine as well as ceremony. The Christian Trinity comprises Father, Son and Holy Spirit, and Eastern and Western churches had disputed how to describe the Spirit’s relationship to the other persons. The bishops retained the formulation that the Spirit proceeds from the Father through the Son, and opposed adding filioque, Latin for “and the Son,” to their creed, the statement of belief recited in worship. Their negotiations thus concerned the words of a service as well as the hierarchy recognized by the church.

The bishops also requested seats in the Commonwealth’s Senate, where Latin Catholic bishops already sat. They did not obtain those seats through the Brest settlement. Their hopes for political equality were therefore distinct from the acceptance of an Eastern-rite church in communion with Rome.

Opposition, violence and parallel hierarchies

Church allegiance affected buildings, endowments, schools and the authority to appoint clergy. A parish accepting a bishop’s claim might come into conflict with a brotherhood or patron who rejected the union. The disputes joined religious conviction to control of institutions that sustained communal life.

Orthodox resistance drew support from noble patrons, urban brotherhoods and Cossacks, frontier military communities with increasing political influence. In 1620, Patriarch Theophanes of Jerusalem consecrated a new Orthodox hierarchy under Cossack protection. Orthodox and union-supporting bishops could now claim leadership over overlapping districts.

Conflict sometimes became violent. Josaphat Kuntsevych, the union-supporting archbishop of Polotsk, was killed at Vitebsk in 1623. The event belonged to disputes over the imposition and rejection of church allegiance, which had already divided local communities. It also became a major part of the Eastern Catholic memory of the union.

Under Władysław IV, political arrangements beginning in 1632 recognized a continuing Orthodox hierarchy. Competition over churches and property still required negotiation and local settlements. Recognition helped establish two durable jurisdictions within the Commonwealth.

Later growth and the meaning of Greek Catholic

The church formed through the union was often called Uniate in historical documents. Greek Catholic is the later designation for these Catholics of the Eastern, or Byzantine, rite. “Greek” refers to the liturgical tradition, while communion with Rome defines their ecclesiastical allegiance. Church Slavonic, a traditional Slavic language of worship, remained important to their services. Local languages also served teaching and other religious communication.

Acceptance continued at different dates. The eparchy of Przemyśl entered the union in 1691, and Lviv in 1700, nearly a century after Brest. Such changes altered the institutional balance in particular regions while Orthodox communities continued elsewhere. The Synod of Zamość of 1720 addressed the Eastern Catholic church’s organization and practice.

Later Ukrainian and Belarusian Greek Catholic traditions developed from this history. Orthodox institutions likewise sustained their own communities. Brest’s lasting consequence was the creation of competing and enduring church allegiances whose practical expression lay in bishops, parishes, schools, patrons and the rites people continued to perform.