The Union of Brest 1596: Kyiv, Rome, Constantinople

What the Union of Brest was

The Union of Brest of 1596 was a union of the Kyiv Orthodox metropolitanate with Rome. It gave rise to the Greek Catholic Church (the UGCC): it combined the Eastern, Byzantine rite with recognition of the primacy of the Pope of Rome^[1]. This was neither an accident nor a “betrayal of Orthodoxy,” but a way out of a deep internal crisis within the church.

A Western orientation — a long-standing tradition

The idea of a union was nothing new for Ukraine. It surfaced as far back as King Danylo Romanovych, who received his crown from the Pope of Rome, and in the mid-fifteenth century the Kyiv metropolitan Isidore took an active part in the Council of Ferrara-Florence^[2]. In other words, a connection with Western, Latin Christianity had deep roots in the Ukrainian church — long before 1596.

Moscow: a new patriarchate with a claim

A point crucial for the present day: in 1589 the Moscow Patriarchate was created — and in violation of canon law at that. The Moscow patriarch was immediately granted the title “of Moscow and all Rus’” and fifth place among the world’s patriarchs. This gave Muscovy formal grounds to lay claim to the Rus’ lands — Ukrainian and Belarusian — that at the time belonged to the Polish-Lithuanian Commonwealth^[3]. For Kyiv this was not a “shared faith” but a political threat.

Kyiv answered to Constantinople, not Moscow

Before the union, the Kyiv metropolitan was subordinate not to Moscow but to the patriarch of Constantinople. But the latter, residing in Ottoman Istanbul under the sultan’s authority, had neither financial nor international influence — he was rather “first among equals” in name only. And when the Constantinople patriarchs tried to interfere in the internal affairs of the Kyiv metropolitanate, this provoked resistance from the local bishops — and became one of the reasons they raised the question of a union: to shut out outside influences and reform their own church^[4].

What this means

The religious history of Ukraine is a direct refutation of the myth that “Orthodoxy = the Russian world.” Kyiv was never a church “appendage” of Moscow: it answered to Constantinople, had its own tradition of conciliar governance and long-standing ties with Rome, and in 1596 deliberately created a separate Greek Catholic Church. Moscow, by contrast, constructed its patriarchate in 1589 — and immediately used it as an instrument for claiming Ukrainian lands. What the Kremlin today presents as an “eternal shared faith” is historically a later political appropriation.