Qianlong reign sixty years, the earliest will of the candidate for the throne is not Jiaqing. At the beginning of his reign, Qianlong secretly set up filial piety Xian Chun Empress Fucha's son Yonglian as the crown prince, but the crown prince did not have the blessing of being the emperor, died in the third year of the Qianlong, and was posthumously awarded as the crown prince of Duanhui. After that, he intended to set Xiaoxian another son Yongcheng as the crown prince, but not yet implemented, less than two years old Yongcheng to Qianlong twelve years of premature death. After losing his favorite son twice, Qianlong was no longer in a hurry to establish an heir. It was not until he was 64 years old in the 38th year of the reign that he secretly established his fifteenth son, Yong Yan, as the crown prince. At this time, many of the emperor has died before him, living son only six son Yongrong, eight son Yongxuan, Yong eleven son Yongxing, fifteen son Yong Yan, seventeen son Yong Lin, of which Yongrong succeeded the side branch, lost the throne succession, Yong Lin is not a good, was also excluded, the remaining three sons compared to Yongxuan, Yongxing is too good, the character is more parochial, is not to do the emperor's suitable candidates, the only choice can only Yong Yan. In order to fulfill the promise of not exceeding the sixty years of Kangxi's reign, Yongxing was openly appointed as the heir in this year, and passed the throne in the following year. After the succession, Qianlong still to "Emperor" as the identity of the real power, until the Jiaqing four of the first month of death, Jiaqing has been three years of the emperor, and the brothers between the name of the ruler and the subject has long been a fixed, so there is no dispute over any extraneous branches.