Forum in Beijing sheds light on a late 12th-century book

At the center of discussions were four volumes of the book, an abridged version of Zizhi Tongjian (Comprehensive Mirror for Aid of Governance). It is a general chronicle of Chinese history from 403 BC to 959 AD, which took Song politician Sima Guang (1019-86) nearly 20 years to finish compiling.

The masterpiece consists of some 294 volumes. It was so famous in later years that people selected different sections of it and published shortened versions, added comments and annotations of rarely used characters.