People of the Revolution and the USSR
- Henri de Saint-Simon Henri de Saint-Simon French thinker who held that society should be led by its productive “industrials”
- Robert Owen Robert Owen Social reformer who emphasized education and cooperation
- Charles Fourier Charles Fourier French social thinker who designed the cooperative phalanstery
- Adolphe Thiers Adolphe Thiers July Monarchy premier who as chief executive in 1871 crushed the Paris Commune and became the Third Republic’s first president
- Karl Marx Karl Marx Author of Capital and leader of the First International
- Friedrich Engels Friedrich Engels Marx's co-author and patron; author of Socialism: Utopian and Scientific
- Ferdinand Lassalle Ferdinand Lassalle Founder of the ADAV, Germany's first workers' party
- Prosper-Olivier Lissagaray Prosper-Olivier Lissagaray Journalist who fought on the Commune’s last barricade and wrote the History of the Paris Commune of 1871 in exile
- Pyotr Alexeyevich Kropotkin Пётр Алексеевич Кропоткин Rurikid prince, founder of anarcho-communism, geographer of Mutual Aid: escaped the Peter and Paul Fortress
- Franz Erdmann Mehring Franz Mehring The elder theoretician of German Marxism: historian, literary critic, and Spartacus League co-founder
- Eduard Bernstein Eduard Bernstein Founder of Marxist revisionism and evolutionary socialism, author of The Preconditions of Socialism
- Karl Johann Kautsky Karl Johann Kautsky Chief theoretician of orthodox Marxism in the Second International, founding editor of Die Neue Zeit, editor of Marx's Capital Vol. IV
- Alexander Lvovich Parvus Александр Львович Парвус Co-author of permanent revolution who arranged Lenin's sealed train: the 'merchant of revolution'