| Clue | Marxist | Birth-Death |
| Leader of the international women's movement. National Executive member of the German Social Democratic party. Long time comrade of Rosa Luxemburg, helped create the Spartacists | |
| Helped create the Russian Social-Democratic party, becoming a Menshevik after the split in the party, but he tried to keep the party united | |
| Member of the ’Left-Communist’ faction which opposed signing of Brest-Litovsk Peace in 1917 in favour of a revolutionary war; Formed right bloc with Zinoviev,Kamenev and Stalin | |
| Indian Communist, agitator, philosopher and key leader of the Comintern | |
| Peruvian writer and agitator. Self-educated. Historian of European Marxism and movements in South America, founded the first communist cell in Peru. | |
| German Left Communist, later lived in the U.S.. Main exponent of “Council Communism” and opponent of idea of Revolution being led by a political party | |
| International Secretary of Fourth International after War; developed theory of 'centuries of deformed workers states' | |
| In the 1950s he joined forces with Charles Taylor, Raphael Samuel, and Gabriel Pearson to launch the journal Universities and New Left Review | |
| American journalist and labor activist. Founder of the Socialist Workers Party & Fourth International in 1938, later founded the International Socialist party | |
| French socialist, participated in the Paris Commune, married to Laura Marx. | |