The Central Committee (CC) composition was elected by the 6th Congress, and sat from 3 August 1917 until 8 March 1918. The CC 1st Plenary Session established the Narrow Composition (abolished October 1917), the Politburo (abolished November 1917) and the Bureau (established in November 1917), while sanctioning the establishment of the Secretariat on the orders of the Narrow Composition.