Omsk is a city and the administrative center of Omsk Oblast, Russia, located in southwestern Siberia 2,236 kilometers (1,389 mi) from Moscow. With a population of over 1.1 million, it is Russia's second-largest city east of the Ural Mountains after Novosibirsk, and seventh by size nationally. During the Imperial era, Omsk was the seat of the Governor General of Western Siberia, and later of the Governor General of the Steppes. For a brief period during the Russian Civil War in -, it served as the capital of the anti-Bolshevik Russian State and held the imperial gold reserves. Omsk is the administrative center of the Siberian Cossack Host. It also serves as the see of the bishop of Omsk and Tara, as well as the administrative seat of the Imam of Siberia. Omsk stretches along the banks of the north-flowing Irtysh at its confluence with the smaller Om River.