These comprise both the Orthodox Churches of the Ukraine and certain Uniat Churches, mostly in the west of the Ukraine, Slovakia, Hungary, and Poland, with colonies in North America. The Uniats were formerly known as the Ruthenian Churches. Their ancestors, who were Slavonic converts of St Vladimir, formed part of the Russian Church until the destruction of Kievan Russia by the Monguls in 1237–40 and the absorption of the Ukraine by Lithuania and Poland. In 1595 the Metropolitan of Kiev and five other bishops petitioned for communion with Rome, achieved by the Union of Brest–Litovsk. After the partitions of Poland (1772–95) most of the Ruthenians, except those of Galicia, passed under the sovereignty of Russia and their Churches were gradually suppressed in favour of the Orthodox Church. The Ruthenians of Galicia came under the sovereignty of Austria. They enjoyed toleration as, in theory, did the Uniat Ruthenians (now usually called Ukrainians) in the independent Poland constituted after 1918. At the time of the Russian Revolution the Orthodox Church in the Ukraine was declared a self-governing exarchate of the Russian Orthodox Church; it became an autonomous Church in 1941. In 1946 the Ukrainian Uniat Church in the Soviet Union and in Poland was suppressed and forced to declare a union with the Orthodox Church of the Ukraine. The Uniats maintained a clandestine existence and in 1989 the Uniat Church in the Ukraine was restored. There are now three Churches of the Byzantine rite in the Ukraine: the Greek-Catholic Ukrainian Church (the ‘Uniats’), the Ukrainian ‘Autonomous’ Orthodox Church, and the Ukrainian ‘Unified’ (previously ‘Autocephalous’) Orthodox Church (created in 1919 in association with a reform movement in Russia, never recognized by other Orthodox Churches, but favoured by the political authorities).
A further Ukrainian community (the Podcarparthian Ruthenians) was created when a majority of the Ruthenian population south of the Carpathians was brought into communion with Rome in 1646 by the Union of Užhorod. Since 1945 this community has been split between the Transcarparthian Ukraine, Slovakia, and Hungary.
There are Ukrainian communities of all jurisdictions in the USA, Canada, Brazil, and Argentina.