Involved in revolutionary activity in Lithuania from 1896. Close to his countryman Dzerzhinskii. Emigrated in 1906. Trade-union activist in Petersburg in 1909.
In 1917, ensured the Petrograd link between Lenin and Helphand through Ganetskii in Stockholm. Member of the Executive Committee of the Petrograd Soviet in 1917. Arrested in July 1917.
Released after the Kornilov affair, August 1917. After the October Revolution, worked in the People’s Commissariat of Justice, 1917-1920. Soviet consul in Austria, 1922-1923.
After 1923, legal expert in the Ministry of Transport. Regarded as the Bolshevik’s top legal expert in 1917.