Most Maris are Christians (converted in the 16th century due to subjugation during the reign of Ivan IV of Russia, the Terrible one "Grozny"), while some are of the Marla faith, Christianity with a significant addition of pre-Christian elements.
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Following the organisation of Muslims in the Soviet Union through Muskom, the Mari Section was set up under the auspices of Narkomnats, the Peoples Commissariat for nationalities. Its task was to facilitate the close union of the Mari people with other people, to abolish anti-Russian mistrust and to raise the "class consciousness" of Mari workers. In practice this involved facilitating grain requisitions by the Soviet state, the recruitment of soldiers for the Red Army and the implementation of Bolshevik control of the society.[1]
Может так надо про русских в первую очередь написать?