Friedrich Engels (; German: [ˈfʁiːdʁɪç ˈʔɛŋl̩s]; sometimes anglicised Frederick Engels; 28 November 1820 – 5 August 1895) was a German philosopher, communist, social scientist, journalist and businessman. His father was an owner of a large textile factory in Salford, England.
Engels founded Marxist theory together with Karl Marx and in 1845 published The Condition of the Working Class in England, based on personal observations and research in Manchester. In 1848, Engels co-authored The Communist Manifesto with Marx and also authored and co-authored (primarily with Marx) many other works. Later, Engels supported Marx financially to do research and write Das Kapital. After Marx's death, Engels edited the second and third volumes. Additionally, Engels organised Marx's notes on the Theories of Surplus Value, which he later published as the "fourth volume" of Capital.