Who was Friedrich Engel?

Answer 1

Engels (sometimes Frederick Engels) was a German-born socialist revolutionary and theoritician. He developed with Marx what they called scientific socialism, today most people refer to it as Marxism. He wrote several works with Marx, most notably The Communist Manifesto and wrote many of his own works (though Marx and Engels always went through each others' stuff before sending it off to the publisher) such as The Condition of the Working Class in England, Anti-Duhring (part of it later published again as the pamphlet Socialism: Utopian and Scientific), and The Origin of the Family, Private Property and the State.