USSR anti-religious campaign (1928–1941)
The USSR anti-religious campaign of 1928–1941 was a new phase of anti-religious campaign in the Soviet Union following the anti-religious campaign of 1921–1928. The campaign began in 1929, with the drafting of new legislation that severely prohibited religious activities and called for an education process on religion in order to further disseminate atheism and materialist philosophy.
Source: Wikipedia — USSR anti-religious campaign (1928–1941) (CC BY-SA 4.0)