The Soviet Union (Russian: Советский Союз, tr. Sovetsky Soyuz), officially the Union of Soviet Socialist Republics (USSR; Russian: Сою́з Сове́тских Социалисти́ческих Респу́блик, tr. Soyuz Sovetskikh Sotsialisticheskikh Respublik; IPA: [sɐˈjus sɐˈvʲetskʲɪx sətsɨəlʲɪˈstʲitɕɪskʲɪx rʲɪsˈpublʲɪk] ( listen); abbreviated СССР, SSSR), was a constitutionally socialist state that existed in Eurasia between 1922 and 1991.
The Soviet Union was a single-party state ruled by the Communist Party from its foundation until 1990. A union of 15 subnational Soviet republics, the Soviet state was structured under a highly centralized government and economy.
The Russian Revolution of 1917 caused the downfall of the Russian Empire. Following the Russian Revolution, there was a struggle for power between the Bolshevik party, led by Vladimir Lenin, and the anti-communist White movement. In December 1922, the Bolsheviks won the civil war, and the Soviet Union was formed with the merger of the Russian Soviet Federative Socialist Republic, the Transcaucasian Socialist Federative Soviet Republic, the Ukrainian Soviet Socialist Republic and the Byelorussian Soviet Socialist Republic.
Adolf Hitler (German: [ˈadɔlf ˈhɪtlɐ] ( listen); 20 April 1889 – 30 April 1945) was an Austrian-born German politician and the leader of the National Socialist German Workers Party (German: Nationalsozialistische Deutsche Arbeiterpartei (NSDAP), commonly referred to as the Nazi Party). He was chancellor of Germany from 1933 to 1945 and dictator of Nazi Germany (as Führer und Reichskanzler) from 1934 to 1945. Hitler is commonly associated with the rise of fascism in Europe, World War II, and the Holocaust.
A decorated veteran of World War I, Hitler joined the German Workers' Party, precursor of the Nazi Party, in 1919, and became leader of the NSDAP in 1921. In 1923, he attempted a coup d'état, known as the Beer Hall Putsch, in Munich. The failed coup resulted in Hitler's imprisonment, during which time he wrote his memoir, Mein Kampf (My Struggle). After his release in 1924, Hitler gained popular support by attacking the Treaty of Versailles and promoting Pan-Germanism, antisemitism, and anticommunism with charismatic oratory and Nazi propaganda. After his appointment as chancellor in 1933, he transformed the Weimar Republic into the Third Reich, a single-party dictatorship based on the totalitarian and autocratic ideology of Nazism. His aim was to establish a New Order of absolute Nazi German hegemony in continental Europe.