Complex sentence: Committee to Defeat Revisionism, for Communist Unity was a small British self-professed Marxist-Leninist group, that had left the Communist Party of Great Britain in 1963 and was sympathetic towards the Communist Party of China and the Party of Labour of Albania.
Split into simpler sentences: Committee to Defeat Revisionism, for Communist Unity was a small British Marxist-Leninist group, that had left the Communist Party of Great Britain in 1963. CDRCU was sympathetic towards the Communist Party of China and the Party of Labour of Albania.