Ukrainian Catholic Church, largest of Eastern Catholic churches, is in communion with Rome since the Union of Brest-Litovsk (1596). Byzantine Christianity was established among Ukrainians in 988 by St.Vladimir (Volodimir) and followed Constantinople (now Istanbul) in the Great Schism of 1054.
Temporary reunion with Rome was effected in the mid-15th century, and a definitive union was achieved at Brest-Litovsk in 1596, when Metropolitan Michael Ragoza of Kiev and the bishops of Vladimir, Lutsk, Polotsk, Pinsk, and Kholm agreed to join Roman communion, on condition that their traditional rights be preserved intact.
Orthodox did not accept the union peaceably and the bishops of Lvov and Przemysl, as well as Orthodox Zaporozhian Cossacks, opposed Catholics. In 1633 the metropolitanate of Kiev returned to Orthodoxy, while Lvov joined the union in 1677, followed by Przemysl in 1692.
The partition of Poland at the end of the 18th century brought all Ukrainians, except those in the province of Galicia, under Russian control. By 1839 the tsarist government had forcibly returned Ukrainian Catholics to Orthodoxy. Galicia meanwhile came under the domination of Austro-Hungarian Empire, and in 1807 it was organized into the metropolitanate of Lviv.
With the occupation of Galicia by Soviet armies in 1939, all church activity was suppressed, and the hierarchy was interned. In 1944 Soviet authorities began to put pressure on Ukrainian bishops to dissolve the Union of Brest-Litovsk. On their refusal, they were arrested and imprisoned or deported. A spurious synod in 1946 broke the union with Rome and “united” Ukrainian Catholics with Russian Orthodox. Not until December 1989, during general liberalization of Soviet life, was Ukrainian Catholic Church again made legal.
Great number of Ukrainians emigrated to Americas and Western Europe between 1880 and 1914 and again after World War II. They are organized into metropolitanate of Canada, with the sees of Winnipeg (metropolitan see), Edmonton, Saskatoon, and Toronto, and metropolitanate of United States, with the metropolitan see of Philadelphia and the eparchies of Stamford and St. Nicholas of Chicago. Apostolic eparchies exist in Australia (Melbourne), Brazil (Curitiba), France (Paris), England (London), and Germany (Munich).