The Communist Manifesto
Also called: Manifesto of the Communist Party, Scientific socialism
Marx and Engels published The Communist Manifesto in London as the programme of the Communist League. It saw history as class struggle and called on workers to unite in revolution.

Karl Marx , Friedrich Engels · Public domain · Source
As the factory system spread with the Industrial Revolution, workers suffered low wages, long hours, child labour and squalid towns. Owen, Saint-Simon and Fourier advocated an early socialism of cooperation and ideal communities; Marx and Engels called this “utopian socialism” and their own theory “scientific socialism”.
Published in German in London in February 1848, the Manifesto opens: “A spectre is haunting Europe — the spectre of communism.” It argued that all history is the history of class struggle and that the conflict between the bourgeoisie and the proletariat would end in a workers’ revolution and a classless society. Closing with “Workers of the world, unite!”, it deeply influenced later socialist movements and the Russian Revolution.