Together with his friend and collaborator Karl Marx, Friedrich Engels is considered one of the most prominent 19th-century German social theorists and the co-founder of Marxism. Despite his upper-class origins, Engels worked toward a more just social order his entire adult life.

Born in Prussia in 1820 to a wealthy textile mill owner, Engels became apprenticed to a commercial firm in Bremen at 17. While there, he became interested in radical philosophy, especially Hegel, which impacted all his subsequent political views and intellectual work. Hoping to dampen his radical ideas, Engels’s father sent him to the family’s mill in Manchester. While there, he met Mary Burns, a radical Irish factory worker who most likely guided his explorations of Manchester’s and Salford’s working-class neighborhoods; the two formed a lasting relationship.

Based on his personal observations of the horrors of child labor and the terrible conditions of factory workers, Engels wrote a series of articles published in journals edited by Karl Marx. These pieces were later collected into The Conditions of the Working Class in England. After this work’s publication, Engels and Marx began a progressively closer collaboration and eventually resettled to Belgium, where they both became involved in the Social Democratic Workers’ Party of Germany and the German Communist League; they eventually co-authored the 1848 Communist Manifesto.