Why did the history of Purple Tongzhi Sword begin in A.D.?

The general history of the first 403 years originated from a dynasty or an emperor, but as a general history, Zi Tongzhi Jian is unusual, which began in the twenty-third year of the Eastern Zhou Dynasty (403 BC). Why is this?

In 453 BC, Han Kang, Wei joined forces to wipe out the Zhi Bo forces in charge of the State of Jin at that time, and mastered the real power of the State of Jin, but it was nominally "Qing", a "courtier" of the Zhou Dynasty, not a vassal. To become a vassal state, it must be appointed by Zhou. At that time, Zhou existed in name only, so in 403 BC, the three clans sent representatives to Zhou to beg for titles, and Zhou complied, making Zhao the marquis of Zhao, Wei Si the marquis of Han, and Han Qian the marquis of Han. At this point, Korea, Zhao and Wei officially became three independent vassal States, and Jin disappeared, which is the famous "three tribes divided into Jin" in history.

Sima Guang compiled history at the behest of Yingzong, aiming to "learn from the ups and downs of previous lives and test the gains and losses of today" and provide historical facts for the monarchs in feudal society to learn from. Since 403 BC, the compilation of age history has its own reasons.

Because of the lack of historical data of predecessors, or because of the historical data of predecessors, Sima Guang did not regard it as "loyal history". But more importantly, Sima Guang believes that "the position of the son of heaven is greater than ceremony, ceremony is greater than points, and points are greater than names. What is a gift? Ji Gang is also; What is a score? This is also; What is a name, but also a public servant. " Birthplace is the most important thing. The incident of "Jin Sanfen" is that "the three public officials stole the monarch's power, violently destroyed his monarch, and divided his country", which is "the king's law must be punished", while "the mighty king, not only can't punish him, but also orders him to be a vassal and a minister who respects the crime of rape". "Although Zhou is still alive, Wang has made rules", so in order to "respect his position"

Furthermore, Sima Guang provided reference for feudal monarchs, and of course he should choose historical facts in similar social patterns. However, with the disintegration of the system of "dividing land into fields" and the emergence of "initial tax mu", the social nature has undergone fundamental changes. By the time of the "Three Jin Dynasties", the pattern of feudal society in China had been formed, similar to that in the Northern Song Dynasty. So he remembered history from then on as a reference for feudal emperors.