The migration of Jews to Leningrad from their former places changed the ratio of the followers of the two general directions within Judaism, the traditionalists (Litvaks and Misnagids) and Chasids. The Chasids had been a substantial group within the city's community already before 1917, but the traditionalists had run it. When some leaders of the community emigrated and others withdrew, the Chasids headed the community. Most of the prayer houses and synagogues registered in the late 1920s and early 1930s were Chasidic. Since it was already impossible to produce religious literature typographically, collections of Chasidic sermons and prayer-books were rewritten by hand. Chasidism gained influence within the Leningrad Jewish community thanks to the fact that the head of the Lubavicher Chasids, the sixth Lubavicher Rebe, lived in Leningrad from 1924 to 1927.
The Habbad's spiritual leader - the 6th Lubavicher Rebe, Iosif Itskhak Shneyerson - moved to Leningrad in 1924 from Rostov-on-the-Don because of the Civil War. His associates moved to Leningrad together with him. For a short time, Leningrad became the global center of the Habbad. The Bolsheviks tried to get the support of this authoritative Jewish religious leader when they organized the Rabbinical Congress, but he rejected participation in the Congress and sent only a short greeting. The actions of the Rabbi seemed suspicious to the members of the Jewish Sections. "We are for Lenin and against the Shneyersons", they declared in the book Against the anti-semites, published in 1928. The book also claimed that Iosif Itskhak Shneyerson spent funds collected by American Jews to spread traditional Jewish institutions in agricultural communes.
The authorities considered the accusations against the Rabbi well founded. Every day, he received Chasids in his apartment and from 100 to 150 people came to him for prayer-meetings. In June, 1927, he was arrested. The arrest took place at night; July nights are light in Leningrad. Some of the participants in the prayer-meeting were still near the house on Mokhovaya Street when they saw the ominous car with OGPU officers. Within hours, they warned all the closest associates of Shneyerson. Anticipating a search, the latter annihilated all compromising documents and letters. The future 7th (the last) head of Habbad, the fiance of the Rabbi's daughter, was also warned. He hid in Luga (a small town in Leningrad Region) in the house of the Luga Rabbi, Gorin.
The arrested Rabbi was put into the internal prison of Leningrad OGPU. He was accused of anti-Soviet subversive activities. After a short investigation, he was sentenced to death. Then, a sequence of the events occurred which Lubavicher Chasids call 'a miracle'. The punishment was changed. At first, the death sentence was commuted to imprisonment; then, imprisonment was changed to deportation to Siberia, and then to Kostroma; finally, deportation to Kostroma was changed to deportation from the USSR.
Chasids explain these miracles to protests by the international Jewish community and the efforts of the Latvian Minister of Trade (of Jewish origin). They say that he agreed to sign a trade contract with the USSR in exchange for the Rabbi's life. In fact, the Rabbi was sentenced to deportation to Kostroma for 3 years. The pivotal role in changing the sentence belonged to the Political Red Cross headed by Yekaterina Peshkova