Ssu-ma Kuang (sō-mä kwäng) [key], 1018–86, Chinese statesman and historian of the Northern Sung dynasty. He edited the monumental Tzu-chih t'ung-chien [the comprehensive mirror for aid in government], a chronicle of Chinese history from 403 B.C. to A.D. 959. The title indicates the belief that history can serve the present as a mirror of the past so that rulers can avoid the same mistakes. The 12th cent. philosopher Chu Hsi abridged and reworked the materials. Ssu-ma Kuang was a member (with Ou-yang Hsiu and Su Tung-p'o) of the conservative bureaucratic party that successfully opposed the reforms of Wang An-shih.