Karl Marx and His Family Active in the revolutions of 1848, Marx fled Germany and eventually settled in London, where he wrote Capital, the weighty exposition of his socialist theories. Despite his advocacy of radical revolution, Marx and his wife, Jenny, pictured here with two of their daughters, lived a respectable though modest middle-class life. Standing on the left is Friedrich Engels, an accomplished writer and political theorist who was Marx’s long-time friend, financial supporter, and intellectual collaborator.