The Metropolis of Kyiv (Greek: Μητρόπολις Κιέβου, romanized: Mitrópolis Kiévou; Ukrainian: Ки́ївська митропо́лія, romanized: Kyivska mytropoliia; Belarusian: Кіеўская мітраполія, Kijeŭskaja mitrapolija) was an autonomous metropolis of the Ecumenical Patriarchate of Constantinople with center in Kyiv after its formation in 988 as a result of the Christianization of Rus by Volodymyr the Great until January 6, 2019, when it received the Tomos on Autocephaly.
In 1596, the Union of Brest was adopted which transferred the ecclesiastical jurisdiction of the metropolis from the Ecumenical Patriarchate to the Holy See. As a sui juris Eastern Catholic particular church, the metropolis retained its ancient rights; in time, it came to be known as the Ruthenian Uniate Church. Some clergy and laity in the Commonwealth continued to give their loyalty to Constantinople but had no hierarchs to support them. In 1620, the Ukrainian Cossacks, led by Hetman Petro Konashevych-Sahaidachny, secured the restoration of the Orthodox hierarchy in the Commonwealth as the Metropolis of Kiev, Galicia and all Rus'.
