After Tang Taizong Li Shimin deposed Prince Li Chengqian, it wasn't long before he deposed King Li Tai of Wei from the throne and demoted him from the capital Chang'an. This incident was actually related to what King Li Tai of Wei himself did. Prince Li Chengqian conspired to rebel, and there was a factor in this that was forced by King Li Tai of Wei. Moreover, Mrs. Li also said some very treasonous words in front of Tang Taizong Li Shimin.
In addition, when Li Chengqian was still the prince, he jumped up and down to form cliques for personal gain. What he did had violated Li Shimin's bottom line, and he didn't know it. This led to Emperor Taizong Li Shimin of the Tang Dynasty, out of multiple considerations, to remove Li Tai from the throne and demote him from the capital. In a sense, Li Tai's experience was his own fault. Li Shimin, Emperor Taizong of the Tang Dynasty, loved Li Chengqian very much, but Li Tai forced him to rebel
Li Chengqian was the first son born to Li Shimin and his favorite empress Changsun. He almost succeeded Li Shimin in seizing the throne. was established as the heir. Li Shimin loved him beyond measure and personally tutored him in handling government affairs. He also found him the best famous teachers and scholars in the world to give him the most comprehensive education. Even Li Chengqian broke his leg while riding a horse and became permanently disabled, but it did not change his status in Li Shimin's heart at all.
However, due to Li Chengqian's special hobby that he could not talk about, he was discovered by Li Shimin and killed Li Chengqian's male favorite on the spot. Li Chengqian felt not only fear but also anger in front of the angry Li Shimin. It is a pity that as the heir to the throne, this kind of hobby is not allowed. However, the occurrence of this incident also allowed the quick-thinking King of Wei Li Tai to see an opportunity.
Li Tai, King of Wei, had been befriending the ministers of the DPRK a long time ago. After the murder of Prince Li Chengqian's male favorite, he began to move up and down, hoping to give Li Shimin a better impression and try to get Li Shimin to change his mind and replace the heir. Moreover, he used public opinion through various channels to attack Li Chengqian, who was still the prince. It can be said that the prince Li Chengqian was in a state of panic all day long, and his anger was ignited by the various operations of Wei King Li Tai, which also amplified the fear in his heart. In the end, he and some people started to plan a rebellion, which ended in complete failure. Li Tai's stupid words made Li Shimin hate him
After the prince Li Chengqian was deposed for treason, Li Tai was naturally happy to spend money. Since the position of prince is still vacant, he naturally has to work harder to fight for it. His various operations finally caught the eye of Li Shimin, and Li Shimin's heart began to loosen gradually. In this case, it is still very likely that Wei King Li Tai will become Prince Li Tai, but everything still requires Li Shimin's approval.
But in a chat between Li Shimin and Li Tai, he heard Li Tai describe his plan after becoming the prince: He would kill all his sons and then establish his younger brother Li Zhi. As the heir to the throne. After saying this, Li Shimin felt particularly harsh. Originally, Li Shimin was not in the right position, but Li Tai also wanted to play this trick of brothers giving way to talents, and also wanted to kill all his sons.
Li Tai was so ruthless that he even killed his own son Hui Hui for the throne. Then a hundred years after Li Shimin, Li Zhi would not only be impossible to be appointed as the heir, but would be the first to be killed. How could Li Shimin not see Li Tai's little thoughts? So after Li Tai said such words, Li Shimin's disgust for him instantly rose to the extreme. In order to keep Li Zhi, Li Tai must lose political influence and stay away from the capital
Perhaps after Li Tai said that, Li Shimin began to pay special attention to Li Zhi. After his investigation, he felt that he was rational and met almost all of his standards for an heir, except that he was still young, immature and weak. Therefore, Li Shimin may have made the decision to establish Li Zhi as his successor after that.
However, since the dangerous element Li Tai is still the King of Wei and remains in the capital Chang'an, some protective measures must be taken for Li Zhi, who is relatively weak-tempered. Therefore, King Li Tai of Wei was deprived of his throne and demoted from the capital in a short period of time. This eliminated his influence in the capital and completely eliminated the possibility of him seeking to usurp the throne.
Conclusion: In order to show his loyalty to his father Li Shimin, Li Tai used too much force and sent himself to the point of no return. No matter which way you look at it, he deserves it. Later facts also proved that Li Shimin's choice was not too wrong.
During the reign of Li Zhi, the territory of the Tang Dynasty expanded to the extreme, and the prestige of the Tang Dynasty also spread to the farthest places. Even Goguryeo, which Li Shimin had not solved, was also destroyed during this period.
If Li Shimin had not done anything to deal with Li Tai, there might be a possibility of royal civil strife within Datang in the future, and this was the last thing Li Shimin wanted to see.