Complex sentence: In 1848, he co-authored "The Communist Manifesto" with Marx, though he also authored and co-authored (primarily with Marx) many other works, and later he supported Marx financially to do research and write "Das Kapital".
Split into simpler sentences: In 1848, he co-authored "The Communist Manifesto" with Marx, and he also authored and co-authored (primarily with Marx) many other works. Later he supported Marx financially to do research and write "Das Kapital".