The Russian Soviet Federative Socialist Republic (Russian: Росси́йская Сове́тская Федерати́вная Социалисти́ческая Респу́блика (РСФСР), transliterated as Rossiyskaya Sovetskaya Federativnaya Sotsialisticheskaya Respublika [RSFSR]), also called the Russian Soviet Federated Socialist Republic, the Russian SFSR, and the RSFSR for short, was the largest and most populous of the fifteen Soviet republics of the Soviet Union. It was by far the largest sub-national entity in the world by area and second in population after the Indian state of Uttar Pradesh. The capital was Moscow, which also served as the capital of the Soviet Union.