Every year the Communist Party of the Soviet Union (CPSU) elected a 27 member Central Committee. In March 1919 the party decided this body was too large to determine policy. It was therefore replaced by a five man Politburo (increased to nine in 1925 and ten in 1930). Its first members were Vladimir Lenin, Leon Trotsky, Joseph Stalin, Lev Kamenev and Nikolai Krestinsky.

In 1952 the Politburo was replaced by a presidium of thirty-six members. After the death of Joseph Stalin it was reduced to ten members.