In the early Zhou Dynasty

the system that younger brother succeeded to the throne from elder brother was adopted. Thus

Zhou Gong succeeded to the throne according to the will of the king of Wu Kingdom. Accordingly

Zhou Gong should leave the throne to other brothers such as Guan Shu or Cai Shu. However

Zhou Gong attempted to reform the succession system

and adopted"Yi Ji Yi Ji"System

which means leaving his throne to his son

then to his son's brother

then to his son's brother's son

and so on. As a result

Guan Shu and Cai Shu's succession hope was ruined and they revolted with Wu Geng. However

their revolt ended with failure. Zhou Gong protected the new succession system. According to the new system

Zhou Gong could leave his throne to his son

Bo Qin. But he left his throne to Cheng Wang

the son of the king of Wu Kingdom to express that he was not selfish. "Yi Ji Yi Ji"System existed in the Western Zhou Dynasty for more than 200 years till the reform of the king Zhou Li who began to leave his throne only to his son instead of leaving it to his brothers. After this

the first son of the lineal descents inheritance system was adopted in Zhou Dynasty. Early in 1920s

scholars from China and other countries have found "Yi Ji Yi Ji" System. However

they were restricted by Wang Guowei's opinion that Western Zhou Dynasty adopts the first son of the lineal descents inheritance system and couldn't make right comment on"Yi Ji Yi Ji" System. Even worse

In 1980s

"Yi Ji Yi Ji" System was completely denied. Therefore

further discussion is needed to reveal the truth of history.