sentences:  In 1831 he became active as a radical student organization member, for which he was imprisoned between 1834 and 1838.In 1846, in Brussels, Wolff became a close friend of Karl Marx and Friedrich Engels.He was active in the Brussels Communist Correspondence Committee and a member of the League of the Just in addition to being Co-founder of the League of Communists in 1848 as a member of its central authority.