Karl Marx (1818?1883) was a German philosopher, economist, political theorist, and sociologist whose ideas profoundly shaped modern political and economic history. Alongside his lifelong collaborator Friedrich Engels, Marx analyzed the mechanics of capitalism, labor, and history, developing the theoretical framework later known as Marxism. Friedrich Engels (1820?1895) was a German philosopher, social scientist, and businessman. He provided essential financial backing and intellectual partnership to Marx, co-authoring several foundational texts and editing the later volumes of Marx's landmark economic study, Das Kapital. Together, their 1848 publication of The Communist Manifesto ignited revolutionary movements across the globe.