Miles Taylor writes:
The best of friends started as the closest of rivals. When Marx first met Engels in 1842 he immediately disliked his theology, his military uniform and the company he kept in the beerhalls of Berlin. Within a couple of years the two were housemates in Paris, co-authoring and co-conspiring their way towards The Communist Manifesto of 1848 and the revolutionary barricades of that momentous year. Over a lifetime, Engels’s devotion to Marx makes Boswell’s acquaintance with Johnson look quite casual. Gofer, editor, agent, translator and financial provider, Engels even stood in as a parent when Marx fathered a child by his maid. Without Engels, Marx would have had no income, and the world would have been deprived of Das Kapital.