|February||Revolution in Russia. The Tsar is replaced by a Provisional Government of elected politicians.|
|November||Second Russian Revolution. The Bolshevik Party, led by Vladimir Lenin, overthrows the Provisional Government.|
|November - December||Lenin begins to set up a Bolshevik dictatorship.|
Civil War in Russia: The Bolsheviks (Reds) eventually won because of their ruthless methods and the unpopularity of the opposition (White) forces.
The involvement of foreign armies in the Civil War left bitter memories for many Russians.
Communist Russia was not invited to join League of Nations.
|1920s generally||There was a widespread fear of Communist revolution spreading to Britain and USA.|
Lenin continued to build a Communist state in Russia.
Russia became Union of Soviet Socialist Republics (USSR).
Stalin succeeded Lenin as leader of the USSR. He became an unopposed dictator.
Stalin also built up Soviet industry to make the USSR a major power by the 1930s.
Worldwide economic depression led to major political problems in Europe, Asia and Africa.
Extreme anti-Communist governments came to power in Japan and Germany.
|1934||Stalin takes the USSR into the League of Nations.|
|1935||Germany's new leader, Adolf Hitler, announced plans for a huge rearmament programme. At the same time as he announced rearmament, Hitler also made clear his hatred of Communism and his desire to smash the USSR.|
|1936-38||Adolf Hitler took control of large areas of central and eastern Europe.|
|1938||Hitler demanded that the Sudetenland area of Czechoslovakia should become part of Germany. At first it looked as though there would be war but, in October 1938, Britain and France effectively gave Hitler what he wanted. Stalin was not consulted and felt betrayed.|
|1939||Stalin no longer trusted Britain and France to oppose Hitler. He agreed a treaty with Hitler in 1939 not to go to war with him. This gave Hitler the freedom he wanted to attack Poland. This in turn led to the outbreak of the Second World War in September 1939.|