Russian Soviet Federative Socialist Republic

The Russian Soviet Federative Socialist Republic (Росси́йская Сове́тская Федерати́вная Социалисти́ческая Респу́блика [РСФСР] 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 and became the Russian Federation after the collapse of the Soviet Union. It was by far the largest sub-national entity in the world by area and 2nd in population after Uttar Pradesh, India. The capital was Moscow, also the capital of the Soviet Union.

The Soviet regime was established on November 7, 1917, following the October Revolution. In Russian official documents of the time it was referred to as Russian Republic, Soviet Republic (Советская Республика), or Russian Soviet Republic, among others. On July 10 1918 the 1918 Constitution was accepted, with the official name of Russian Socialist Federative Soviet Republic; the most recent variant of the name (with "Socialist" and "Soviet" swapped), was adopted in the 1937 Constitution.

In English, the term Bolshevist Russia or Soviet Russia is commonly used for the period 1917–1922.

RSFSR was recognized internationally by only a few states: the Irish Republic, Estonia, Finland, Latvia and Lithuania. The four last-mentioned countries recognized RSFSR in the Treaty of Tartu, 1920.

The RSFSR became part of the Soviet Union in 1922, an act formalised by the 1924 Soviet Constitution.

On April 17, 1946 the Kaliningrad Oblast — the north of the former German province of East Prussia — was annexed by the USSR and made part of the Russian SFSR. Nikita Khrushchev transferred Crimea from the Russian SFSR to the Ukrainian SSR in 1954.

The Congress of Soviets of RSFSR voted to leave the Soviet Union on December 12, 1991. The RSFSR was renamed the Russian Federation on December 25.

Autonomous Soviet Socialist Republics (ASSRs) within the Russian SFSR

 * Bashkir ASSR (1919–1990)
 * Buryat ASSR (1923–1990)
 * Crimean ASSR (1921–1945)
 * Dagestan ASSR (1921–1991)
 * Yakut ASSR (1922–1991)
 * Kabardino-Balkar ASSR (1921–1991)
 * Kalmyk ASSR (1935–1943; 1958–1992)
 * Karakalpak ASSR (1932–1936)
 * Karelian ASSR (1923–1940; 1956–1991)
 * Komi ASSR (1921–1993)
 * Mari ASSR (1920–1991)
 * Mordovian ASSR (1930–1993)
 * Northern Ossetian ASSR (1924–1993)
 * Udmurt ASSR (1920–1991)
 * Volga German ASSR (1918–1941)
 * Tatar ASSR (1920–1990)
 * Chechen-Ingush ASSR (1936–1944; 1957–1990)
 * Chuvash ASSR (1925–1990)
 * Tuva ASSR (1961–1992)
 * Kirghiz ASSR (1920–25), then Kazakh ASSR (1925–1936)
 * Mountain ASSR (1921–1924)