The Diocese of Harbin was a diocese within the Russian Orthodox Church that was established in Manchuria to support the large numbers of Russian believers who had established domicile in Manchuria. These believers came, first, to support the Russian built and run China-Eastern Railway and, second, to escape the Bolshevik regime in Russia after the Russian Civil War in 1920. A diocese was formally formed in the early 1920s by the Russian Orthodox Church Outside Russia and later was governed by the Church of Russia when Soviet forces occupied Manchuria in the latter half of 1945. The diocese was disbanded in accordance with the Sino-Soviet treaty of 1956 that required departure of all non-Chinese clergy.