Friedrich Engels

A very special business angel: The self-effacing friend who enabled “Das Kapital” to be written, The Economist, August 13, 2009, review of 'Marx’s General: The Revolutionary Life of Friedrich Engels', by Tristram Hunt, published in Britain as The Frock-Coated Communist: The Revolutionary Life of Friedrich Engels'

No Marx without Engels, by Tristram Hunt, author of The Frock-Coated Communist, History Today, April 2009 (via Arts & Letters Daily)

Marxists Internet Archive