It was established in 1917 as an
Apostolic exarchate, this being the Eastern Catholic pre-diocesan equivalent of an
Apostolic vicariate; hence it was directly subject to the
Apostolic See and its
Congregation for the Eastern Churches and not part of any
ecclesiastical province. It was established in territory that previously exclusively belonged to the Latin Metropolitan
Roman Catholic Archdiocese of Mohilev. In June (O.S. May) 1917, the first synod of the Russian Greek Catholic Church was held, where
Leonid Feodorov was chosen as exarch and a number of measures to establish the church were accepted. The exarchate of Russia was officially recognized by
Pope Benedict XV in 1921, and before that it had been subordinated to Ukrainian Metropolitan
Andrey Sheptytsky. After the arrest and exile of Leonid Feodorov by the Soviets in the late 1920s, the exarchate was placed under the Latin Catholic Apostolic Administration of
Moscow, led by Bishop
Pie Eugène Neveu, SJ. Neveu received Russian Orthodox into the Catholic Church in secret over the following years, before he left the country in 1936. Among those was the Orthodox bishop
Bartholomew Remov, who was appointed by Neveu as bishop for the Russian Byzantine Catholic exarchate. In 1942 the borders of the exarchate were defined as including "ethnic
Great Russia,
Finland, and
Siberia." == Ordinaries ==