The article explores the genesis and transformation of Soviet ethno-confessional communities in the 1940s – 1960s, using the case of the so called «new» Mennonite communities in the Ural and Siberia. The development of these communities depended on the extreme conditions of a transition they went through, from the traditional rural life to the urban industrial setting. In these communities we see new mechanisms of solidarity, based on inter-communal and inter-religious communication.