Why did the emperor always set up fifteen elder brothers instead of twelve elder brothers?

In fact, Qianlong had already established a prince at the beginning of his reign, but all the princes he established died of illness, so for a long time, Qianlong didn't want to establish a prince again. Later, when I was old and wanted to establish a prince, I chose May 15th. But many people are curious, why didn't Qianlong value his son so much before, and why didn't he make twelve elder brothers Yongji a prince?

First, among all Yongji's mediocre sons, May Yongqi is his favorite. Just like in many TV dramas, May Yongqi is smarter and more talented, and has long been named a prince by Qianlong. At that time, Yong Qi was basically the default prince, but Yong Qi later died of illness, so Gan Long had to change to the prince, and Gan Long's remaining sons were not very good. 12. Moreover, Yongji's mother is Gan Long's stepfather. It is said that Gan Long was offended at that time, and she was snubbed by Gan Long. Soon she died of illness. Gan Long never liked the queen, so she probably didn't like her son.

Second, there is nothing to choose from in Qianlong. Qianlong itself refers to the eldest son inheritance system, but both princes have died, and the remaining sons are of the same clan. So Qianlong can only choose from the rest. The quality of Ganlong's sons is generally not high. Some people let him handle things badly, some have no intention of being an artist, and some are young. Ganlong loves him more, so he has a stubborn temper. There are no outstanding advantages, but he is good at studying hard and is dignified and generous on weekdays. Even if Gan Long didn't have much confidence in him, there was nothing he could do.

Third, Yongji's mother is not favored by Yongji's mother. As mentioned above, after he succeeded to the throne, he was not favored, and it was difficult for Qianlong to like Yongji. Yongji died in his twenties and had no chance to be an emperor. Even if Unara becomes the queen, she will certainly be inferior to Queen Fu Cha in Qianlong's heart, and Qianlong loves your concubine very much, so he has a crush on Yan Yong, your concubine.