1820-1895. German social and political philosopher, a friend of, and collaborator with, Karl Marx on The Communist Manifesto 1848 and other key works. His later interpretations of Marxism, and his own philosophical and historical studies such as Origins of the Family, Private Property, and the State 1884 (which linked patriarchy with the development of private property), developed such concepts as historical materialism. His use of positivism and Darwinian ideas gave Marxism a scientific and deterministic flavour which was to influence Soviet thinking. In 1842 Engels's father sent him to work in the cotton factory owned by his family in Manchester, England, where he became involved with Chartism. In 1844 his lifelong friendship with Karl Marx began, and together they worked out the materialist interpretation of history and in 1847-48 wrote the Communist Manifesto. Returning to Germany during the 1848-49 revolution, Engels worked with Marx on the Neue Rheinische Zeitung newspaper and fought on the barricades in Baden. After the defeat of the revolution he returned to Manchester, and for the rest of his life largely supported the Marx family. Engels's first book was The Condition of the Working Classes in England 1845. The lessons of 1848 he summed up in The Peasants' War in Germany 1850 and Revolution and Counter-Revolution in Germany 1851. After Marx's death Engels was largely responsible for the wider dissemination of his ideas; he edited the second and third volumes of Marx's Capital 1885 and 1894. Although Engels himself regarded his ideas as identical with those of Marx, discrepancies between their works are the basis of many Marxist debates.