believers to atheism." Under the doctrine of state atheism in the Soviet Union, a "government-sponsored program of forced conversion to atheism" was conducted by the Communists. The Communist Party destroyed churches, mosques and temples, ridiculed, harassed, incarcerated and executed religious leaders, flooded the schools and media with anti-religious teachings, and it introduced a belief system called "scientific atheism", with its own rituals, promises and proselytizers. Many priests were killed and imprisoned; thousands of churches were closed. In 1925 the government founded the League of Militant Atheists to intensify the persecution. The League of Militant Atheists was also a "nominally independent organization established by the Communist Party to promote atheism". The Communist regime confiscated church property, ridiculed religion, harassed believers, and propagated atheism in the schools. Actions towards particular religions, however, were determined by State interests, and most organized religions were never outlawed. It is estimated that 500,000 Russian Orthodox Christians were martyred in the gulags by the Soviet government, excluding the members of other Christian denominations who were also tortured or killed. The main target of the anti-religious campaign in the 1920s and 1930s was the Russian Orthodox Church, which had the largest number of faithful worshippers. A very large segment of its clergy, and many of its believers, were shot or sent to labor camps. Theological schools were closed, and church publications were prohibited. In the period between 1927 and 1940, the number of Orthodox Churches in the Russian Republic fell from 29,584 to less than 500. Between 1917 and 1940, 130,000 Orthodox priests were arrested. The widespread persecution and internecine disputes within the church hierarchy lead to the seat of Patriarch of Moscow being vacant from 1925 to 1943. After Nazi Germany's attack on the Soviet Union in 1941, Joseph Stalin revived the Russian Orthodox Church in order to intensify patriotic support for the war effort. By 1957, about 22,000 Russian Orthodox churches had become active. But in 1959, Nikita Khrushchev initiated his own campaign against the Russian Orthodox Church and forced about 12,000 churches to close. By 1985, fewer than 7,000 churches remained active. In the Soviet Union, in addition to the methodical closure and destruction of churches, the charitable and social work which was formerly done by ecclesiastical authorities was taken over by the state. As with all private property, Church owned property was confiscated and converted to public use by the state. The few places