Why did Kangxi pass the throne to Zisi? What are the conditions?

It has become a general trend for the emperor to pass the throne to heirs other than the first eldest son.

First of all, Kangxi passed the throne to Yongzheng because Yongzheng was not only outstanding, but also had a strong position and ruling ability in the court.

The eldest son inheritance system has been the strictest way to change rights since China. However, since the dispute of the Western Han Dynasty, Kangxi handed over power to Yongzheng, which is also the inevitable result of the disadvantages of the eldest son system. Sometimes the eldest son born first is likely to be short of talent. As can be seen from historical cases, Cao Cao has come up with many ways to change his power, among which Cao Pi and Cao Zhe are particularly prominent. Moreover, his ability to handle state affairs is very strong, but he failed to inherit Cao Cao's rights, which is also the disadvantage brought by the eldest son system. Kangxi gave power to Yongzheng because the boss didn't have the strength to rule the court and establish his own prestige. Yongzheng helped Kangxi solve the problem of victims in his early years, and he also had a strong reputation and status in the court, so the inheritance system would not cause much political turmoil in this respect. At that time, Kangxi specially invited a fortune teller to calculate for himself how many years his court could last. The fortune teller told Kangxi that handing over power to the talented descendants of Yongzheng could last for generations. This statement also confirms Yongzheng's reputation among the people and the court.

Secondly, Kangxi chose fourteen sons Yongzheng as emperor because of his love, and Yongzheng's support rate behind the court was much higher than that of other heirs.

According to relevant historical records, among all his sons, Kangxi had the best relationship with Yongzheng, and when Yongzheng was young, Kangxi had been handling state affairs for him. In education, Kangxi was also very concerned about Yongzheng's education. Of course, Yongzheng is also excellent, and writing poems and articles also has a certain foundation. Later, Kangxi faced the emptiness of the national treasury, and Yongzheng solved this problem and set a certain example in the corruption of the imperial court at that time.