[4] Following the partitions of Poland, the eparchies of the Ruthenian Uniate Church (Latin: Ecclesia Ruthena unita)[5][6] were liquidated in the Russian Empire and the Kingdom of Prussia.

Both "bishops" hired mercenaries and fought a pitched battle over control of the Eparchy, before the Polish king finally stepped in and appointed one of the two candidates to an adjacent Orthodox See.

As the result of being alienated from both Polish Latin Catholicism and Russian Orthodoxy, the Greek Catholic church in Ukraine had developed its own separate, Ukrainian identity.

[17] The pro-Latin members of the synod were removed; and the Church began to disintegrate, with its parishes in Volhynia reverting to Orthodoxy, including the 1833 transfer of the famous Pochaiv Lavra.

[17] In the years following and preceding the Partitions, Catherine the Great played a huge rule in forcefully dismantling the Greek Catholic Church in Ukraine.

[13] Following the failure of Kościuszko Insurrection and the final partition of Poland, the persecution of Ukrainian Greek Catholics intensified, and the church was forbidden from accepting converts from Orthodoxy.

[23] As a result of the reforms, over the next century the Greek-Catholic Church in Austrian Galicia ceased being a puppet of foreign interests and became the primary cultural force within the Ukrainian community.

In 1924, following a visit with Ukrainian Catholic believers in North America and western Europe, the head of the UGCC was initially denied reentry to Lwów (the Polish name at the time for Lviv), only being allowed back after a considerable delay.

[28] In 1945, Soviet authorities arrested, deported, and sentenced to forced-labor camps in Siberia and elsewhere the church's metropolitan Yosyf Slipyi and nine other Greek Catholic bishops, as well as hundreds of clergy and leading lay activists.

Moreover, the western dioceses of Lviv-Ternopil and Ivano-Frankivsk were the largest in the USSR and contained the majority of the Russian Orthodox Church's cloisters (particularly convents, of which there were seven in Ukrainian SSR but none in Russia).

Orthodox canon law was also relaxed on the clergy allowing them to shave beards (a practice uncommon to Orthodoxy) and conduct liturgy in Ukrainian as opposed to Church Slavonic.

Pope Paul VI demurred, but compromised with the creation of a new title of major archbishop (assigned to Yosyf Slipyi on 23 December 1963[31] ), with a jurisdiction roughly equivalent to that of a patriarch in an Eastern church.

"[32] The weakened Soviet authorities were unable to pacify the situation, and most of the parishes in Galicia came under the control of the Greek-Catholics during the events of a large scale inter-confessional rivalry that was often accompanied by violent clashes of the faithful provoked by their religious and political leadership.

The Ukrainian Greek Catholic Church predominates in three western oblasts of Ukraine, including the majority of the population of Lviv, but constitutes a small minority elsewhere in the country.

[36][37][38] The church has followed the spread of the Ukrainian diaspora and has some 40 hierarchs in over a dozen countries on four continents, including three other metropolitan bishops in Poland, the United States, and Canada.

[45] Several leading prelates, including Major Archbishop Sviatoslav Shevchuk, denounced the invasion and used their connections to the wider Catholic Church to gather support and provide information on the situation on the ground.

Despite a few moments of tension between the leadership of the UGCC and Rome, namely over the inclusion of a Russian woman alongside a Ukrainian during the 2022 Good Friday Via Crucis, and the Pope's words regarding the assassination of Darya Dugina, Shevchuk often emphasised Francis' support for Ukraine during the war.

These actions reflect a broader strategy of using religion to justify violence and exert control, tied to the Kremlin and Moscow Patriarchate’s promotion of the "Russian World."

Two UGCC priests, Fathers Ivan Levitsky and Bohdan Geleta, were detained in Berdyansk in November 2022 and remain in harsh conditions in Russian custody, facing severe mistreatment, including torture.

Archbishop Borys Gudziak noted that religious institutions in Russia function only if aligned with state policies, a practice now being enforced in occupied Ukrainian regions.

[61] On 6 February 2023, the Archeparchy of Przemyśl–Warsaw, taking into account the previous decision of the Ukrainian Greek Catholic Church in Ukraine[59] and the opinion of the Delegates of the Joint Diocesan Council in Porszewice in June 2022, adopted a decree on the transition to the Revised Julian calendar from 1 September 2023.

[62][63] On 22 March 2023, the Eparchy of Saints Peter and Paul of Melbourne, according to the decree of Bishop Mykola Bychok, decided that from 1 September 2023, the UGCC in Australia and Oceania will completely switch to the Gregorian calendar, including Easter.

[64] According to the decree of Bishop Bohdan Dziurakh dated 22 April 2023, from 1 September 2023, the Ukrainian Catholic Apostolic Exarchate of Germany and Scandinavia completely switches to the Gregorian calendar, including Paschal, in contrast to the UGCC in Ukraine, in Poland.

[65] On 9 June 2023, the Ukrainian Catholic Eparchy of the Holy Family of London, according to the decree of Bishop Kenneth Nowakowski, switches from 1 September 2023 to the Gregorian calendar, in particular with Easter.

They maintain this characteristic by resisting the use of English in liturgies and, in some parishes, insisting on the use of the Julian Calendar to calculate dates of Christmas, Easter, and other religious holidays, thus placing themselves outside the U.S. mainstream.

Even before the Second Vatican Council the Holy See declared it important to guard and preserve the customs and distinct forms for administering the sacraments in use in the Eastern Catholic Churches (Pope Leo XIII, encyclical Orientalium Dignitas).

According to his biographer Cyril Korolevsky, Metropolitan Andrey opposed use of coercion against those who remained attached to Latin liturgical practices, fearing that any attempt to do so would lead to a Greek-Catholic equivalent of the 1666 Schism within the Russian Orthodox Church.

Meanwhile, among Byzantine Catholics in Western Ukraine, forced into a persecuted and secret existence following the Soviet ban on the UGCC, the latinizations remained, "an important component of their underground practices",[78] in illegal parishes, seminaries, and religious communities.

"[82] In 1999, Basil Kovpak and two other traditionalist UGCC priests asked Society of Saint Pius X Superior General Bishop Bernard Fellay to become their spiritual leader.

The Society also consists of a group of Greek Catholic nuns, who were forced to leave the Basilian Order in 1995, "because of their 'traditionalist' ideas"[83] and who now reside in the house where Blessed Nicholas Charnetsky died following his release from the Gulag.