Who will succeed to the throne if the eldest son dies?

The eldest son inheritance system originated from the creation of Zhou Gong in the Western Zhou Dynasty. The biography of the Spring and Autumn Ram is summarized as "establishing an official by virtue instead of virtue, and establishing an official by value instead of length".

Once established, the chieftain system, as a basic or ideal form of excessive inheritance of the highest rights of the state, was inherited by the autocratic dynasties of later generations and was regarded as an "eternal right". Under normal circumstances, the eldest son is the best condition for obtaining the throne. For example, Zhu Yuanzhang, the Ming emperor, chose the son (eldest grandson) of the prince as the legal heir when the prince died young.

Therefore, under normal circumstances, after the death of the eldest son, the throne is inherited by the eldest son. However, in reality, the emperor's internal affairs system is often disturbed or destroyed by the emperor's own likes and dislikes, and powerful forces, such as eunuchs, concubines and so on, often interfere with the implementation of the internal affairs system for their own interests.