Complex sentence: Acting against advice, which foretold of his economic ruin if he became politically active, he relegated his theatrical career to advocate the cause of the Republican forces of the Spanish Civil War, and he then became active in the Council on African Affairs (CAA).
Split into simpler sentences: Acting against advice, which foretold of his economic ruin if he became politically active, he relegated his theatrical career to advocate the cause of the Republican forces of the Spanish Civil War. He then became active in the Council on African Affairs (CAA).