Under Stalin, the Soviet Union underwent forced agricultural collectivization which caused resistance from peasants. Stalin also launched the Great Purge starting in 1934 where he had the secret police target old Bolsheviks, army heroes, factory managers, writers, and regular citizens. Through torture and threats to families, people were forced to confess to crimes and around 4 million people were purged. Stalin consolidated his power through state propaganda, censorship, purges, and terror using the secret police. Atheism became official policy and the government seized church property and killed priests.