Most of the people living in the Russian Empire were members of the Russian Orthodox Church. In 1721 the Orthodox Church became a government department called the Holy Synod. It was run by the Chief Procurator, an official appointed by the Tsar.
Completely under the control of the government, the Orthodox Church played an important role in the various russification campaigns (forbidding the use of local languages and the suppression of religious customs). t also became closely associated with the Jewish Pogroms that took place during the last part of the 19th century.
As a state department the Russian Orthodox Church lost the right to plead with the Tsar on behalf of the poor and dispossessed. The church was therefore seen by those seeking reform as a reactionary institution condoning serfdom.
The Bolsheviks, as Marxists, regarded religion as the "opium of the masses". After the October Revolution the Soviet government were extremely hostile to the Church.
In January 1918 the Soviet government passed legislation that attempted to separate the Church from the state and education. They also deprived the Church of all legal functions concerning the family and marriage.
During the Civil War all church buildings, funds and property were confiscated. It is estimated that around a thousand priests were killed during this period.
A decree passed on 14th April 1929 established that the Church could not own property nor establish central funds, or make compulsory levies. Their religious activities are confined to worship within the registered congregation. They were also forbidden to engage in missionary or welfare work.
None of the new cities and industrial centres, built under the Five Year Plans, included churches. Old churches were pulled down and by the 1930s Moscow only had a dozen churches compared to over 200 before the October Revolution.
In 1937 there was 30,000 registered religious communities. During the purges this figure dropped significantly and by 1939 it was only 20,000. However, it was estimated that there was a large number of unregistered congregations.