Friedrich Engels (/ˈɛŋɡəlz/;[1] German: [ˈfʁiːdʁɪç ˈɛŋəls]; 28 November 1820 – 5 August 1895) was a German social scientist, author, political theorist, philosopher, and father of Marxist theory, together with Karl Marx. In 1845 he published The Condition of the Working Class in England, based on personal observations and research in Manchester.