an Eastern Catholic church of the Byzantine rite, in communion with Rome since the early 20th century. A small number of Orthodox Russians, influenced by Vladimir Solovyov, a philosopher and theologian, converted to Catholicism (c. 1900), retaining their rite. Just before the Russian Revolution of 1917, they received their own exarch, Leonid Fyodorov; in 1921, however, Fyodorov was imprisoned, and the exarchy was dispersed under the communists.

About 2,500 Russian Catholics escaped Russia's new communist regime and settled in western Europe. There is one Russian Catholic bishop residing in Rome and a Russian studies institute, Istina, run by Dominicans, at Boulogne-Billancourt, Fr.