The incident of the Nine Sons Seizing the Heir took place in the later years of Emperor Kangxi of the Qing Dynasty. Its background was complex and full of drama.
First of all, Emperor Kangxi reigned for too long, resulting in many princes. Among them, Prince Yinfeng was the leader, but he was deposed due to improper behavior, which caused other princes to covet the position of heir apparent. In the forty-seventh year of Kangxi's reign (1708), Prince Yinfeng was deposed for the first time, then re-established, but was deposed again a year later. This series of events intensified the power struggle between the princes.
In this process, multiple factions were formed, such as the Fourth Master Party, the Eighth Master Party, etc. Each prince increased his bargaining chips by making friends with ministers and gaining support from the army.
In the end, the fourth elder brother Yinzhen (i. E. Emperor Yongzheng) stood out with his calmness, wit and political wisdom and successfully ascended the throne as emperor.