The Soviet Union,[a] officially the Union of Soviet Socialist Republics[b] (USSR[c]), was a socialist federation in Eurasia that existed from 1922 to 1991. Nominally a union of multiple national Soviet republics,[d] its government and economy were highly centralized. The country was a one-party state, governed by the Communist Party with Moscow as its capital in its largest republic, the Russian Soviet Federative Socialist Republic (Russian SFSR). The Russian nation had constitutionally equal status among the many nations of the union, but exerted de facto dominance in various respects.[13] Other major urban centres were Leningrad, Kiev, Minsk, Alma-Ata and Novosibirsk. Extending across the entirety of Northern Asia and much of Eastern Europe, the Soviet Union had spanned eleven time zones and incorporated a wide range of environments and landforms. From northwest to southeast, the Soviet Union shared land borders with Norway, Finland, Poland, Czechoslovakia, Hungary, Romania, Turkey, Iran, Afghanistan, China, Mongolia and North Korea. It shared its maritime borders with Japan by the Sea of Okhotsk and the U.S. state of Alaska across the Bering Strait. With an area of 22,402,200 square kilometres (8,649,500 sq mi), the Soviet Union was the largest country in the world by area, covering more than one-eighth of the Earth's inhabited land area,[14][15][16] and the third most populous, with over 288 million people as of 1989, with 80% of the population living in the western, European part of the country. The Soviet Union had its roots in the October Revolution of 1917, when the Bolsheviks led by Vladimir Lenin overthrew the Russian Provisional Government which had replaced Tsar Nicholas II during World War I. In 1922, the Soviet Union was formed by the Treaty on the Creation of the USSR which legalized the unification of the Russian, Transcaucasian, Ukrainian and Byelorussian republics that had occurred from 1918. Following Lenin's death in 1924 and a brief power struggle, Joseph Stalin came to power in the mid-1920s. Stalin committed the state's ideology to Marxism–Leninism (which he created) and constructed a command economy which led to a period of rapid industrialization and collectivization. During this period of totalitarian rule, political paranoia fermented and the late-1930s Great Purge removed Stalin's opponents within and outside of the party via arbitrary arrests and persecutions of many people, resulting in over 600,000 deaths.[17] Suppression of political critics, forced labor were carried out by Stalin's government. In 1933, a major famine that became known as the Holodomor in Soviet Ukraine struck multiple Soviet grain-growing regions, causing the deaths of some 3 to 7 million people.[18] In August 1939, days before the start of World War II, the USSR signed the Molotov–Ribbentrop Pact agreeing to non-aggression with Nazi Germany, after which the two countries invaded Poland in September 1939. In June 1941, the pact collapsed as Germany turned to attack the Soviet Union, opening the largest and bloodiest theatre of war in history. Soviet war casualties accounted for the highest proportion of the conflict in the effort of acquiring the upper hand over Axis forces at intense battles such as Stalingrad and Kursk. The territories overtaken by the Red Army became satellite states of the Soviet Union and the postwar division of Europe into capitalist and communist halves would lead to increased tensions with the West, led by the United States of America. The Cold War emerged by 1947 as the Eastern Bloc, united under the Warsaw Pact in 1955, confronted the Western Bloc, united under NATO in 1949. On 5 March 1953, Stalin died and was eventually succeeded by Nikita Khrushchev, who in 1956 denounced Stalin and began the de-Stalinization of Soviet society through the Khrushchev Thaw. The Soviet Union took an early lead in the Space Race, with the first artificial satellite and the first human spaceflight. Dissatisfied with Khrushchev's policies, the Communist Party's conservative wing led a coup d'état against Khrushchev in 1964, quietly ousting him without any bloodshed. In the early 1970s, there was a brief détente of relations with the United States, but tensions resumed with the Soviet–Afghan War in 1979. In the mid-1980s, the last Soviet leader, Mikhail Gorbachev, sought to reform and liberalize the economy through his policies of glasnost (openness) and perestroika (restructuring). Under Gorbachev, the role of the Communist Party in governing the state was removed from the constitution, causing a surge of severe political instability to set in. The Cold War ended during his tenure in 1989 as Soviet satellite states in Eastern Europe and overthrew their respective communist governments. With the rise of strong nationalist and separatist movements inside the union republics, Gorbachev tried to avert a dissolution of the Soviet Union in the post-Cold War era. A March 1991 referendum, boycotted by s
Austria-Hungary, often referred to as the Austro-Hungarian Empire or the Dual Monarchy in English-language sources, was a constitutional union of the Austrian Empire (the Kingdoms and Lands Represented in the Imperial Council, or Cisleithania) and the Kingdom of Hungary (Lands of the Crown of Saint Stephen or Transleithania) that existed from 1867 to 1918, when it self-dissolved at the end of World War I. The union was a result of the Austro-Hungarian Compromise of 1867 and came into existence on 30 March 1867. Austria-Hungary consisted of two monarchies (Austria and Hungary), and one autonomous region: the Kingdom of Croatia-Slavonia under the Hungarian crown, which negotiated the Croatian–Hungarian Settlement (Nagodba) in 1868. It was ruled by the House of Habsburg, and constituted the last phase in the constitutional evolution of the Habsburg Monarchy. Following the 1867 reforms, the Austrian and the Hungarian states were co-equal. Foreign affairs and the military came under joint oversight, but all other governmental faculties were divided between respective states.