List of leaders of the Soviet Union
Following Joseph Stalin's consolidation of power in the 1920s, the post of the General Secretary of the Central Committee of the Communist Party became synonymous with leader of the Soviet Union, because the post controlled both the Communist Party and the Soviet Government, both indirectly, via Party membership, and via the tradition of a single person holding two highest posts: in the Party and in the government. The post of the General Secretary was abolished in 1952 under Stalin and later re-established by Nikita Khrushchev under the name of First Secretary. In 1966, Leonid Brezhnev reverted the office title to its former name. Being the head of the Communist Party of the Soviet Union (CPSU), the office of the General Secretary was the highest in the Soviet Union until 1990. The post of General Secretary lacked clear guidelines of succession, so after the death or removal of a Soviet leader the successor usually needed the support of the Politburo, the Central Committee, or another government or party apparatus to both take and stay in power. The President of the Soviet Union, an office created in March 1990, replaced the General Secretary as the highest Soviet political office.
Communist Party of the Soviet Union
The CPSU was a Communist party, organized on the basis of democratic centralism. This principle, conceived by Lenin, entails democratic and open discussion of policy issues within the party followed by the requirement of total unity in upholding the agreed policies. The highest body within the CPSU was the Party Congress, which convened every five years. When the Congress was not in session, the Central Committee was the highest body. Because the Central Committee met twice a year, most day-to-day duties and responsibilities were vested in the Politburo, (previously the Presidium), the Secretariat and the Orgburo (until 1952). The party leader was the head of government and held the office of either General Secretary, Premier or head of state, or some of the three offices concurrentlybut never all three at the same time. The party leader was the "de facto" chairman of the CPSU Politburo and chief executive of the Soviet Union. The tension between the party and the state (Council of Ministers of the Soviet Union) for the shifting focus of power was never formally resolved, but in reality the party dominated and a paramount leader always existed (first Lenin and thereafter the General Secretary).