People of the Revolution and the USSR

Social Democratic Party of Germany (SPD) Non-Bolshevik socialists 1826–1900 ○ Natural causes

Co-founder of the Eisenach party and drafter of the Gotha Programme

"Nobody has combatted State Socialism more than we German Socialists, nobody has shown more distinctively than I, that State Socialism is really State capitalism!" — 'Our Recent Congress' (1896)

Born in Giessen, he joined the risings of 1848 and fled by way of Switzerland to London, where he spent twelve years as a close associate of Marx and Engels. In 1869 he founded the Social Democratic Workers' Party with August Bebel at Eisenach; arrested for opposing war credits, he was convicted at the Leipzig treason trial of 1872. He was the man who brought off the Gotha unity congress of 1875 and drafted its programme, the document Marx took apart line by line. From 1890 until his death he edited the party paper Vorwärts. He was the father of Karl Liebknecht.

Social Democratic Party of Germany (SPD) Non-Bolshevik socialists 1840–1913 ○ Natural causes

Co-founder of the SPD who led the German workers' movement for over 40 years, the 'shadow emperor' of the working class

"The struggle in Paris is only a small outpost skirmish; the main affair in Europe is still ahead of us. Before a few decades have passed, 'War on the palaces, peace to the cottages' will become the battle cry of the entire European proletariat." — Reichstag, 25 May 1871

A woodturner's apprentice who co-founded the Social Democratic Workers' Party with Wilhelm Liebknecht in 1869 and, through the Gotha unity congress of 1875, built the SPD into the world's largest socialist party. Under the Anti-Socialist Laws (1878–1890) he ran the illegal party paper from Zurich exile and held the underground organisation together; he steered the adoption of the Erfurt Programme (1891), which became the Marxist benchmark for European social democracy, and led the orthodox defence against Eduard Bernstein's revisionism. His Woman and Socialism (1879) ran through over fifty editions as the founding text of socialist feminism, and his funeral in 1913 drew the leaders of the Second International.

Social Democratic Party of Germany (SPD) Non-Bolshevik socialists 1850–1932 ○ Natural causes

Founder of Marxist revisionism and evolutionary socialism, author of The Preconditions of Socialism

"I have extraordinarily little interest in what is called the 'final goal of Socialism.' This aim, whatever it be, is nothing to me, the movement everything." — Response to critics (1899)

German SPD theorist and politician. Engels's literary executor and editor of Der Sozialdemokrat, Bernstein began as an orthodox Marxist before his 1899 The Preconditions of Socialism challenged Marx's predictions of capitalist collapse, class polarization, and revolutionary necessity. His dictum "the goal is nothing, the movement everything" laid the foundation for social democracy's reformist, parliamentary turn, creating the schism between revolutionary socialism and evolutionary social democracy. He broke with the SPD's pro-war majority to co-found the anti-war USPD during World War I, and spent his final years defending Weimar parliamentary democracy, dying six weeks before Hitler took power.

Independent Social Democratic Party of Germany (USPD) Non-Bolshevik socialists 1854–1938 ○ Natural causes

Chief theoretician of orthodox Marxism in the Second International, founding editor of Die Neue Zeit, editor of Marx's Capital Vol. IV

"Socialism as a means to the emancipation of the proletariat, without democracy, is unthinkable." — The Dictatorship of the Proletariat (1918)

Leading Marxist theoretician of the Second International. He authored the Erfurt Programme, refuted Bernstein's revisionism, and after the Russian Revolution critiqued Bolshevik rule, creating the defining point of divergence between social democracy and Leninism.

Social Democratic Party of Germany (SPD) Non-Bolshevik socialists 1867–1924 ○ Heart attack

Co-author of permanent revolution who arranged Lenin's sealed train: the 'merchant of revolution'

In December 1917, Lenin refused Parvus's request to return to Russia with the words: 'the cause of the revolution should not be touched by dirty hands.'

A Marxist theorist and journalist in the German SPD who co-developed the theory of permanent revolution with Leon Trotsky in 1904–1905. During World War I, he built a revolutionary network inside Russia with German government funding and played the decisive role in arranging Lenin's return via the 'sealed train' in April 1917. After the Bolsheviks took power, Lenin refused his request to return, declaring that 'the cause of the revolution should not be touched by dirty hands'; Parvus remained in Germany and became an advisor to early Weimar Republic leaders. Criticized for commodifying his principles between revolutionary Marxism and realpolitik, he remains one of the most controversial figures of 20th-century socialism.