1917: Bending to riots by women, striking workers and defecting soldiers, Czar Nicholas II abdicates, thereby ending the Romanov dynasty ("february revolution). Aleksandr Kerensky is appointed by the Duma as prime minister of the provisional government . Bolsheviks overthrow the Kerensky government and install Lenin as leader of Russia ("October Revolution")
1918: Czar Nicholas II, his wife and their children are killed by the secret police of the Bolsheviks . The Bolshevik government introduces a policy of food requisition and peasant revolts break out throughout Russia . Lenin orders the secret police to arrest and/or kill the anarchists . Lenin signs a truce with Germany and accepts territorial losses . Lenin nationalizes the factories, collectivizes the farms and outlaws the church . Civil war erupts between the Red Army of the Bolsheviks and the Mensheviks (helped by Britain, Japan, USA) . Lenin changes the name of the Bolshevik party to Russian Communist Party .
1919: The Bolshevik government enacts a policy of extermination of the Cossacks (8,000 are executed in the next two months). The Comintern (or "Third International") is founded in Moscow with the aim of spreading the revolution all over the world.
1920: The ruble has lost 96% of its pre-war value; Industrial production has fallen to 10% of its 1913 level.
1921: The civil war ends with Lenin's victory (millions have died of starvation, the population of Petrograd has dropped from 2.5 million in 1917 to 0.6 in 1920). Lenin enacts the New Economic Policy (sometimes called “state capitalism”)
1922: The Soviet Union is created by uniting Russia, Ukraine, Belarus and Transcaucasus (Armenia, Georgia, Azerbajan) . Five million people have died during two years of famine, mostly in the lower Volga; the anti-religious campaign has killed 2691 priests, 1962 monks and 3447 nuns in 1922 .
1924: The Soviet Union adopts a constitution based on the dictatorship of the proletariat. Lenin dies and is succeeded by Joseph Stalin
1927: The Soviet Union launches a campaign of eradication of Islam
1928: Stalin enacts the first Five-Year Plan for rapid industrialization of the Soviet Union
1929: Stalin calls for full collectivization and orders the persecution of "kulaks" (rich farmers), 15 million peasants are deported to the Arctic regions and 6.5 million die . 1,778,000 people are convicted of crimes in 1929.
1930: More than 20,000 people are sentenced to death in the Soviet Union in 1930.
1932: one million people in Kazakhstan die of famine (caused by forced collectivization).
1933: five million people in Ukraine die of famine (caused by forced collectivization).
1934: Stalin's main advisor, Sergei Kirov, is assassinated, prompting Stalin to begin the "Great Purge" of the Communist Party (thousands of communists are deported to "gulags"); 2.5 million Soviet citizens are arrested and 700,000 are executed over the next three years.
December 1935: The Gulag has 800,000 prisoners in camps and 300,000 in work colonies .
1936: The first show trial against communist leaders is held in Moscow (the defendants "confess").
May 1937: Stalin begins the purge of the Red Army (in 18 months 3 out of 5 marshals, 13 out of 15 army generals, 8 out of 9 admirals and a total of 35,000 officers are liquidated) .
1939: Stalin and Hitler sign a non-aggression pact including the partition of Poland (and assigns the Baltic states to the Soviet Union); World War II begins when Germany invades Poland on September 1; Soviet union invades Poland September 17