Until 1917, the Russian Empire was an absolute monarchy. The monarchy was sustained mainly by the gentry, owner of the most arable land. Shortly before World War I, Russia had the largest population in Europe, with around 171 million inhabitants in 1904. Also was confronted with the greatest social problem of the continent: the extreme poverty of the general population. Meanwhile, the liberal and socialist ideologies permeated the country, developing an awareness of revolt against the nobles.
With the development of industrialization and greater relationship with Western Europe, Russia received the new political currents outside clashed with the old fashioned absolutism of the Russian government. Among them stood out the chain inspired by Marxism, which led to the Russian Social Democratic Workers Party. In 1903, disagreements as to the form of action led party members RSDLP to split into two basic groups: Mensheviks and Bolsheviks.
In this context that initiates the conflict in 1917 with the aim of overthrowing the Russian autocracy and bring to power the Bolshevik Party, Vladimir Lenin. The first phase of the Revolution, also known as the February Revolution overthrew the autocracy of Tsar Nicholas II, the last Tsar to rule, and sought to establish in its place a liberal republic die.
In the second phase known as the October Revolution, in which the Bolshevik Party, overthrew the Provisional Government and imposed Soviet Socialist government and followed with 4 more years of civil war until 1921.
After the civil war, in December 1922, was held a general congress of all the soviets place the foundation of the Union of Soviet Socialist Republics (USSR). With Lenin, the founder of the first socialist state, died in January 1924 initiating then a great internal struggle for Soviet power dispute with Stalin victorious. From December 1929, Stalin became the absolute dictator of the Soviet Union. During the Stalinist period (1924-1953) it is estimated that the Soviet political terror was responsible for the imprisonment of more than five million people and the death of over 23 million people.
Was successful in rebuilding the country and the increase of economic and cultural level of the Soviet population making the USSR, together with the United States after World War II (1939-1945) one of the world's superpowers.
With the victory of the allies, the Soviet Union, the main opponent of Germany in Europe now has enormous international prestige. The Stalin's rule ended with his death in 1953. The Soviet Union was the first socialist country in the world, which lasted until 1991.