People of the Revolution and the USSR

Socialist Revolutionary Party (PSR/SR) Non-Bolshevik socialists 1850–1919 ○ Natural causes

The great unifier of the Russian revolutionary movement, from the Chaikovtsy to the Left SRs

'I have complete discord with Lenin... I no longer believe in Lenin' — in 1919, on the eve of exile, breaking with the Bolsheviks after half a century of shared struggle.

Mark Natanson was a pivotal organizer who built the institutional backbone of the Russian revolutionary movement across half a century: co-founding the Circle of Tchaikovsky, Land and Liberty, and the People's Rights Party, and serving on the Central Committee of the Socialist Revolutionary Party. Known as the 'Ivan Kalita of the revolution' for his talent in unifying dispersed circles, he stood with Lenin as an internationalist at the Zimmerwald and Kienthal conferences during the First World War. In 1917 he led the formation of the Left SRs and later the Party of Revolutionary Communism, backing the Bolsheviks through the October Revolution, but grew disillusioned as the regime turned toward one-party dictatorship, leaving the words 'I no longer believe in Lenin' before fleeing into exile.

Russian Social Democratic Labour Party (RSDLP) Non-Bolshevik socialists 1850–1928 ○ Natural causes

Theorist of the mass workers' party: the argument that lost to Lenin's vanguard

Trotsky recalled: 'An atmosphere of simplicity and sincere comradely participation reigned in the Akselrod household.'

A former narodnik, he co-founded the Emancipation of Labour group (1883) with Plekhanov and Zasulich, the first Russian Marxist organisation. As an Iskra editor (1900) and, after the 1903 RSDLP split, the central theoretician of Menshevism, he argued for a mass, democratic workers' party against Lenin's vanguard model. He served on the Petrograd Soviet executive in 1917 but opposed the October Revolution and spent his final decade in exile, active in the Second International.

Russian Social Democratic Labour Party (RSDLP) Non-Bolshevik socialists 1856–1918 ○ Natural causes

The father of Russian Marxism: against his own pupils’ revolution

After the October 1917 seizure of power, Plekhanov said: "Russian history has not yet ground the flour from which the wheat pie of socialism will be baked."

He began as a Populist and transplanted Marxism into Russia: Lenin’s whole generation learned from his books. But returning in 1917 after thirty-seven years abroad, he condemned the October rising as premature, a violation of history’s stages. He died of tuberculosis under the regime his pupils had built, and his funeral became a half-opposition demonstration.