From 1931 he was head of the Patriarchal Exarchate for Orthodox Parishes of Russian Tradition in Western Europe.

In 1928 Metropolitan Sergius (Stragorodsky), then locum tenens of the Patriarchate of Moscow, demanded declarations of loyalty to the Soviet regime, a proposition which Eulogius initially supported but subsequently repudiated.

In 1930, after taking part in a prayer service in London in supplication for Christians suffering under the Soviets, Eulogius was removed from office by Sergius and replaced.

After Eulogius's death (8 April 1946), Metropolitan Seraphim (Lukyanov) of Western Europe was appointed the new exarch by the Moscow Patriarchate.

A large number of parishes, opposed to Seraphim, once again entered the Patriarchate of Constantinople, forming the basis of the exarchate which continued to 2018.