KARL MARX (1818-1883) is today considered one of the world's seminal thinkers; although at his death he was, in his own words, "the best hated and most calumniated man of his time." Born in Trier, Prussia, he was descended from a rabbinical family. At the University of Bonn and later at the University of Berlin, he joined a group of radicals who espoused the ideas of Hegel. After emigrating to Paris in 1843 he became deeply committed to communism and the overthrow of tyranny. Here too he began his lifelong association with Friedrich Engels. Finally settling in London with his wife and family, Marx lived the rest of his life in abject poverty while creating his masterwork, Das Kapital, and becoming the leading spirit of revolution throughout the world. FRIEDRICH ENGELS (1820-1895) is known primarily as the intellectual companion of Karl Marx. The son of a German textile manufacturer, Engels became the collaborator and staunch supporter of Marx before and during the European revolutions of 1848, when together they created The Communist Manifesto. When Engels outlived his friend by twelve years, he dedicated himself to editing Marx's manuscripts and completing the two volumes of Das Kapital left unfinished. A true friend to the end, he willed all his property to Marx's children.