Stalin established his position as ruler of the Soviet regime within a few years after Lenin's death in 1924. Through shrewd and brutal politicking, he was able to defeat his rivals, notably Leon Trotsky, and entrench his power.
Stalin responded to poor agricultural production in the late 1920s by a program of expropriating grain from peasants in Siberia. He also began a massive nationwide offensive to force the peasants to collectivize. Thousands of peasants died, and millions were force to relocate.
To consolidate his power in the mid-1930s, Stalin launched a campaign of political terror. The purges, arrests, and deportations to labor camps touched almost every family. Large numbers of party, industry and military leaders (like Kotov in "Burnt By the Sun") disappeared, including many of the most loyal and productive members of the Soviet regime. Major Soviet figures like Zinoviev, Kamenev and Bukharin admitted to "crimes against the state" in show trials, after which they were put to death. These confessions came about through coercion, or in some cases, as true believers in Communist ideology, people "confessed" willingly.
The climate of fear created by the new political secret police (KGB) was a major component of the system which came to be known as Stalinism.
Three years after his death in 1953, the 20th Party Congress denounced Stalin and his legacy. Many of the people who had been labelled as traitors during the Stalin era were subsequently cleared and their reputations were "rehabilitated," often posthumously, like Kotov in "Burnt By the Sun."