Li Yuan, the Emperor Gaozu of Tang, was the founding emperor of the Tang Dynasty. In the chaotic era at the end of the Sui Dynasty, Li Yuan saw the opportunity to rebel in Taiyuan, and then had a far-sighted vision and seized Guanzhong as a base area and a large rear area, showing his extraordinary foresight. In the subsequent Tang Dynasty war to unify the whole country, Li Yuan was good at employing people, from good as a stream, commanding Ruoding, and finally swept away the crowd and Dingding Heshan. Among the founding emperors of the past, Li Yuan's talent was also enough to rank among the best.
However, Li Yuan was confused for a while, and made a big mistake in dealing with the issue of the heir to the throne. On the one hand, he followed the custom of li concubines and established his eldest son Li Jian as crown prince. But on the other hand, he attached great importance to the outstanding military ability of his second son, Li Shimin, and entrusted him with a heavy responsibility, as a result, Li Shimin made many military achievements, his prestige increased day by day, and he won the hearts and minds of the military and the people. In this way, between Li Shimin and Crown Prince Jiancheng, a dispute over the heir to the imperial throne will inevitably break out.
In this dispute, the two have their own advantages. The crown prince Li Jiancheng was backed by his father Li Yuan, but Li Shimin had extensive influence and a large number of confidants in the army and military generals. The two show their abilities, show their own means, and fight openly and secretly. On the fourth day of June in the ninth year of wude in the Tang Dynasty, the contradiction between Li Shimin and Li Jiancheng was completely intensified. The Xuanwumen Revolution, which determined the fate of the Tang Dynasty, broke out.
The change of Xuanwu Gate was a general decisive battle between Li Shimin and Li Jiancheng. In the end, due to the abundance of civilian and military talents under Li Shimin, Fang Xuanling Du Ruhan and others offered advice, wei Chi Jingde, Duan Zhixuan, Qin Shubao and others charged into the battle and won a complete victory in this battle. For his own throne, Li Shimin also wielded a butcher's knife mercilessly, not only beheading the crown prince Jiancheng and Li Yuanji, the king of Qi, but also killing almost all of their children and descendants.
The prince has been in operation for many years, and his power in the DPRK and China is also intertwined. In order to completely eliminate the prince's power, Li Shimin then launched a round of purges. The Old Book of Tang records that "there were about a hundred people waiting for Jiancheng, and they sat together from the seat", and a group of Li Jiancheng's henchmen suffered a catastrophe at this time, and all of them were beheaded and confiscated from the family property. Because the scope of the blow was too wide and the number of people was too large, Wei Chi Jingde could not see past it, and dissuaded Li Shimin from "being the second murderer of the sinner, and now he has been punished, and if he is more like a disciple, it is not a strategy to take peace."
Seeing that Li Jiancheng's forces had been cleared away, Li Shimin was relieved. However, he was so secretive that he forgot to kill someone. This person later brought Li Shimin a big trouble and almost overthrew the Tang Dynasty. He was the governor of Youzhou at that time, the general of Zuo Yiwei, the commander of the Tianjie Army, the assassin of Jingzhou, and the king of Yan County, Luo Yi.
Luo Yi, born in a family of sui dynasty martial generals, Wu De submitted to the Tang Dynasty for three years. Luo Yi's temperament is fierce and violent, but he is also coarse and thin, cunning and deceitful, strong in martial arts, "brave in attacking and good at shooting", and is a famous general in the late Sui and early Tang dynasties. In the struggle between Crown Prince Jiancheng and Li Shimin, Luo Yi, after some deliberation, decided that Li Jiancheng had the support of his father Li Yuan and would definitely become emperor in the future, so he turned to Li Jiancheng.
In order to show loyalty to Li Jiancheng, Luo Yi did not hesitate to openly provoke contradictions with Li Shimin. Once, "Emperor Taizong tasted his camp and beat him for no reason", one of Li Shimin's subordinates went to Luo Yi's camp to do business, but Luo Yi beat him in public for no reason, so as to demonstrate to Li Shimin. Li Shimin was very angry and complained to Li Yuan, and Li Yuan did not seriously deal with it.
However, Luo Yiwan did not expect that in the change of Xuanwumen, Li Shimin won a great victory and eventually became the emperor of the Tang Dynasty. However, Li Shimin made a mistake in his busy life and forgot to kill Luo Yi, Li Jiancheng's confidant, which resulted in a catastrophe. In the first year of Zhenguan, one year after the change of Xuanwu Gate, Luo Yi officially rebelled after some meticulous preparations.
Luo Yi himself was able to recruit good warriors, had a prestigious reputation, had a elite army of tens of thousands of people, and what was even more frightening was that Luo Yi also secretly colluded with the powerful Hu tribe Jieli Khan in the north and had close relations. Luo Yi also controlled the important town of Youzhou in northern Xinjiang, and if Youzhou was dedicated to Jieli Khan, the central plains would open its doors in an instant. If he and Jieli Khan had joined forces to march south, the result would have been disastrous for Li Shimin, because the newborn Tang Dynasty was not a rival to Jieli Khan at that time, and the Tang Dynasty was likely to be destroyed.
Li Shimin urgently dispatched Changsun Wuji and Wei Chi Jingde to lead a large army to Youzhou to suppress the rebellion. Fortunately, there was an unexpected large-scale mutiny in Luo Yi's army, and the rebel army was torn apart and disintegrated. Luo Yi saw that the situation was out of control, so he had to flee to the Northern Jieli Khan with hundreds of his own soldiers. On the way, his relatives and soldiers again had infighting, Luo Yi was killed, and a generation of tyrants completed their lives. Li Shimin was able to escape the disaster without any danger.
References: New Book of Tang, Old Book of Tang