USSR anti-religious campaign (1921–1928)
The USSR anti-religious campaign (1921–1928) was a campaign of anti-religious persecution against churches and Christian believers by the Soviet government following the initial anti-religious campaign during the Russian Civil War. The elimination of all religion and its replacement with scientific materialism was a fundamental ideological goal of the state.
Source: Wikipedia — USSR anti-religious campaign (1921–1928) (CC BY-SA 4.0)