Bolsheviks faced opposition from day one in power. Thousands of "Anti-Bolsheviks" were sent to labour camps.
The Cheka implemented the Red Terror during the Civil War. This was meant to eliminate "enemies of the people".
Lenin issued a "ban on factions" in 1921. This was meant to curb criticism.
Stalin exploited Lenin's methods. He intensified Terror in particular.
Stalin eliminated actual opposition and potential opposition. This included members of the Central Committee.
Stalin feared his colleagues would betray him because of his wife's suicide and criticism of collectivisation.
A million members of the Communist Party were excluded from 1932-33. Purges on senior members were systematic after that.
Kirov was killed in 1934. Stalin used this as a pretext with Trotskyite and Zinoviev-Kamenev members by arresting multiple factions of the party.
Trotskyites and the Zinoviev-Kamenev factions existed in the Communist Party at the time of Kirov's murder.
Zinoviev and Kamenev were shot at a "show trial" in 1936. 14 Bolsheviks were also killed.
Key Bolshevik leaders and military high commanders were executed in 1937.
Bukharin, Rykov and Yagoda - former head of NKVD were shot in 1938.
Trotsky was assassinated in Mexico in 1940.
Stalin's terror was increasingly aimed at citizens from 1938 onwards. The public were encouraged to inform the government about "hidden enemies".
The planning of arresting citizens was similar to planning industrial production targets. Hundreds of thousands of people were executed or died in prison.
1 in 18 people were arrested during the purges.
One lesser known element of the purges was the deportation of national minorities. Poles and Germans are examples of this.
Stalin deported national minorities during the purges as he feared they would join an invading army. 100,000 Poles were shot during the campaign.
Stalin called a halt to the terror in November 1938 because the people were frightened.
Stalin achieved elimination of all opponents as a result of the purges. He replaced these people with Stalinists.
Stalin obtain control of the Party and the people post-purges.
Martin Sixsmith stated that "class enemies were rounded up and executed for their social origin" after the 1918 Lenin assassination attempt.
D. Volkogonov said Stalin began the purges because he was "driven by a powerful need to win".
Orlando Figes said the Great Terror was an amalgam of "Party purging and great show trials".