Do you know why Li Shimin let go of the Zheng family after occupying the Yang family? Next, the editor of the History Encyclopedia will explain it to you

In the ninth year of the Wude reign of the Tang Dynasty, Li Shimin launched the “Xuanwu Gate Incident” and killed Crown Prince Li Jiancheng and Prince Qi Li Yuanji.
Subsequently, Li Shimin did an unexpected thing by taking Yang, the wife of his younger brother, Prince Qi Li Yuanji, into the palace and becoming his concubine.
In today’s eyes, this matter may seem inferior to animals, but in the Tang Dynasty, where the Xianbei tradition still existed, it was understandable. However, since Li Shimin occupied Yang, why did he let go of Li Jiancheng’s wife Zheng?

To answer this question, we need to figure out what kind of person Li Shimin is
Li Shimin is definitely not a lecherous and debauched ruler, but a highly intelligent and cunning politician. Every decision he makes must achieve maximum benefit.
Li Shimin would never do anything that harms others and benefits oneself. So, he treated Li Jiancheng’s wife Zheng Shi and Li Yuanji’s wife Yang differently, both due to a comprehensive consideration of multiple factors.
The hatred of killing her son made it impossible for Zheng to surrender to Li Shimin
In 626 AD, Li Shimin launched the shocking “Xuanwu Gate Incident” that shocked the Tang Dynasty. He ambushed Crown Prince Li Jiancheng and Prince Qi Li Yuanji, and successfully shot and killed them in one fell swoop.
Shocked by it!
In order to permanently eliminate future troubles, the next day Li Shimin executed Li Jiancheng’s five sons, all of whom were born to the Zheng family. This means that Li Shimin and the Zheng family had a hatred for killing their sons. How could she be with Li Shimin?
What deeper hatred can a woman have than the hatred of killing her child? And not one of the five sons will be left behind! Even if Li Shimin forcibly incorporates the Zheng family into the harem, can he rest assured?
However, Yang did not give birth to a son or a daughter for Li Yuanji, and the hatred was not so deep. It was not unacceptable for Li Shimin to be included in the harem in the end! You should know that the Li family in Longxi and Hu Feng are still alive, and women are private property!
The hatred of killing her husband, Zheng regarded Li Shimin as a vengeful bandit
The marital relationship between Zheng and Li Jiancheng is far from comparable to the relationship between Yang and Li Yuanji.
Li Jiancheng and Li Yuanji, one is a noble crown prince and the other is a distinguished prince. Although they may not have as many concubines and palaces as the emperor, there are also many women around them, with more than ten always present!
In the feudal dynasty era, the relationship between husband and wife determined the number of times they were favored, and the number of times they favored determined the number of children they had! Li Jiancheng and Zheng gave birth to five sons and several daughters, which fully demonstrates their exceptionally strong marital relationship!
Li Shimin shot and killed Li Jiancheng, leaving Zheng heartbroken. How could she entrust herself to Li Shimin again? However, Yang and Li Yuanji did not have any children, and later she gave birth to a son for Li Shimin. It indicates that Yang’s fertility is not a problem.
It can only be said that Li Yuanji did not love Yang very much, so he did not pay much attention to Li Yuanji’s death.
The Zheng family of Xingyang and the Yang family of Hongnong are both aristocratic families, and their marriage to the royal family naturally carries the color of political alliance, but there is a difference in marital relationship between husband and wife. This difference in closeness determines the mentality of Zheng and Yang!
The hatred of killing her son and the hatred of killing her husband make it impossible for Zheng to be with Li Shimin!
Zheng is “of advanced age” and is the eldest sister-in-law
Li Jiancheng is 9 years older than Li Shimin. When the Xuanwu Gate Incident occurred, Li Jiancheng was nearly forty years old, and the age of Crown Princess Zheng was almost the same as him! In ancient times, this was already considered a case of aging.
Compared to the charming Yang, Zheng is a bit older!
Moreover, the Yang family did not give birth, like a flower waiting to bloom, while the Zheng family had already given birth to several children, exhausted their youth and energy, and suffered from tragic changes, looking even more haggard. How could they be seen by Li Shimin?
Furthermore, from a moral perspective, there has always been a saying that the elder sister-in-law is like a mother. Even if Li Shimin disregards secular morality, he still has to take care of his father’s face, right?
The main reason why Li Shimin spared the Zheng family is because of the large family behind the Zheng family.
No matter how cold-blooded and cruel Li Shimin was, he had to take this into consideration, so Zheng was able to preserve his life with “chastity”.
Although Li Shimin spared Zheng and allowed her to live in a corner of Chang’an. Zheng lived until 676 AD, at the age of 77. Eventually, with the tacit approval of Emperor Gaozong of Tang, she was buried with Li Jiancheng.
Zheng and Li Jiancheng were never together in life, but they slept together in death and can rest in peace.