Involved in revolutionary activity from the 1890s. Member of the mezhraiontsy group of the SDs, and accepted with them into the Bolshevik Party, 1917. Active participant in the Bolshevik take-over in October 1917.
Member of the Constituent Assembly. Head of the Soviet government peace delegation during negotiations with the Germans at BrestLitovsk, 1918. Defended Trotsky’s position of ‘neither peace, nor war’.
Soviet Ambassador in Berlin, 1918. Head of the Soviet peace delegation to the Baltic countries (Estonia, Latvia, Lithuania) and Poland, 1920. Head of the Turkburo of the Central Committee of the Bolshevik Party, 1921.
Member of the Soviet delegation at the Genoa conference, 1922. Soviet Ambassador to China, 1922. Soviet Ambassador to Austria, 1924.
Prominent member of the group of Trotsky supporters in opposition to Stalin. Committed suicide.