The principal text of the
Zizhi Tongjian comprises a year-by-year narrative of the
history of China over 294 scrolls, sweeping through many Chinese historical periods (
Warring States, Qin, Han, Three Kingdoms, Jin and the Sixteen Kingdoms, Southern and Northern dynasties, Sui, Tang, and
Five Dynasties), supplemented with two sections of 30 scrolls each—'tables' () and 'critical analysis' (). Sima Guang departed from the format used in traditional Chinese dynastic histories, consisting primarily of 'annals' () of rulers and 'biographies' () of officials. Instead, Sima shifted from a 'biographical style' () to a 'chronological style' (). Guang wrote in a memorandum to the Emperor: Since I was a child I have ranged through histories. It has appeared to me that in the annal-biography form the words are so diffuse and numerous that even an erudite scholar who reads them, again and again, cannot comprehend and sort them out. ... I have constantly wished to write a chronological history roughly in accordance with the form of the Tso-chuan (), starting with the Warring States and going down to the Five Dynasties, drawing on other books besides the Official Histories and taking in all that a ruler ought to know—matters which are related to the rise and fall of dynasties and connected with the joys and sorrows of the people, and of which the good can become a model and the evil a warning. Initially, Sima Guang hired Liu Shu () and Zhao Junxi as his main assistants, but Zhao was soon replaced by Liu Ban (), a Han history expert. In 1070 Emperor Shenzong approved Guang's request to add Fan Zuyu (), a Tang history expert. Because the
Zizhi Tongjian is a distillation from 322 disparate sources, the selection, drafting, and editing processes used in creating the work as well as potential political biases of Sima Guang, in particular, have been the subject of academic debate. == Derivative and commented works ==