Stalin Era

Lenin's death early in 1924 occasioned a bitter struggle for power. The principal antagonists were Trotsky and Joseph Stalin, then general secretary of the party, both of whom claimed to be the rightful executors of Lenin's policies. In contrast to Trotsky, who was primarily an intellectual, a theorist, and a gifted military leader, Stalin was a clever and determined organizer. Through his control of the party apparatus, Stalin succeeded in winning the support of a majority within the party and in consolidating his rule. In November 1927 a party referendum completely repudiated Trotsky's policies, expelled him from the party, and exiled him to Almaty. Two years later he was banished from the Soviet Union. In 1940 he was assassinated in Mexico, presumably by an agent of Stalin.

In 1929 Stalin was recognized as the supreme leader of the party and the country. He then began the series of purges that marked his 25 years of rule, turning first against his former allies in the struggle with the Trotskyists. These leaders, notably Nikolay I. Bukharin and Aleksey I. Rykov, were driven from the higher councils of the party.
Thereafter, Stalin relied solely on his control of the party and the police, and on colleagues he had elevated to power. Important among these were Vyacheslav M. Molotov, Valerian V. Kuybyshev, Grigory K. Ordzhonikidze, and Kliment Y. Voroshilov.

Union Constitution and Recognition

During the 1920s sweeping changes were made in governmental administration and marked improvements were achieved in the internal economy and foreign affairs of the country. Up to the end of 1923 the territory which was controlled by the Soviet government comprised the Russian Soviet Federated Socialist Republic, the eastern halves of Belorussia and the Ukraine, and the Caucasus. A plan of federation was drawn up under Stalin's supervision, and in January 1924 a new constitution was put forward, reorganizing the areas under Soviet control into the Union of Soviet Socialist Republics. The new state was initially composed of the Russian, Ukrainian, Transcaucasian, and Belorussian Soviet Socialist republics. Although a degree of local autonomy was granted to each republic, a tight control over foreign affairs, defence, and economic planning was kept by the central Soviet government.