In June 621, Li Shimin defeated Wang Shichong and Dou Jiande, two great rivals, in the Battle of Luoyang, and since then, the Tang Dynasty's unification of the world has been unstoppable.
The north had been fully unified by the Tang Dynasty, and half of the south had begun to fall under Tang rule.
When Li Shimin returned to Chang'an in triumph, the whole city was boiling, and cheers came and went. Dressed in golden armor, he escorted Wang Shichong and Dou Jiande, who were once fierce rivals, to worship in the Taimiao Temple.
Along the way, 10,000 knights and 30,000 armor soldiers lined up to greet them, and the scene was spectacular, showing Li Shimin's supreme glory. In order to commend Li Shimin's merits, Tang Gaozu Li Yuan felt that the existing official position was not enough to carry Li Shimin's merits, so he specially set up a new official position called "General Tiance" and awarded it to Li Shimin.
Since then, Li Shimin has the power to open the government and set up officials, and he can openly recruit Tiance Mansion**, and his power is as powerful as the sky. However, this prominent power also put Li Shimin in an embarrassing situation.
Li Shimin, the mainstay of the Tang Dynasty, has fought in the south and the north since Taiyuan raised his army, and he has conquered everything. In particular, the Battle of Luoyang laid the cornerstone of the unification of the Tang Dynasty. As Li Yuan's prince, he was made King of Qin and was given an additional rank after each victory.
Even after the First World War in Luoyang, Li Yuan had to create a new official position in recognition of his merits. However, with the improvement of Li Shimin's status, the situation of the crown prince Li Jiancheng began to become delicate.
In the Tang Dynasty, Li Yuan was the No. 1 person, and the crown prince was the No. 2 person, but as Li Shimin's official position became higher and higher, the gap between him and Li Jiancheng became smaller and smaller, especially after Li Shimin was named General Tiance and could open the government on his own to recruit **, the gap between the two sides was further narrowed.
Li Shimin's entitlement means that he is no different from Li Jiancheng in other aspects except that he does not have the title of prince.
Li Yuan began to perceive the contradiction between Li Jiancheng and Li Shimin, and he knew that in the face of power, his own brothers could also turn against each other. So, he decided to limit Li Shimin's military power.
Although the Tang Dynasty was not yet fully unified, the remaining enemies were weaker. Li Yuan believed that even if Li Shimin no longer went to the battlefield, the Tang Dynasty would be able to complete the great cause of reunification. Li Shimin also guessed the thoughts of Li Yuan and Li Jiancheng, and after returning to Chang'an, he did not have any dissatisfaction with Li Yuan's restrictive methods, but honestly became his Tiance general, founded the Literature Museum, recruited many well-known Confucians, and showed the attitude of completely letting go of military power and focusing on academic research.
However, a sudden incident shattered this calm, and Dou Jiande's subordinate Liu Heimin rebelled again.
Li Yuan did not pay attention to Liu Heimin's first army, he believed that Dou Jiande had been defeated by Li Shimin, and Liu Heimin's generals raised troops again just to resurrect. He thought that as long as he sent other generals and increased his troops, he could easily deal with Liu Heimin.
However, he never expected that Liu Heimin's strength was far beyond his imagination. Previously, Li Shimin made a surprise attack on Dou Jiande outside the Tiger Prison Pass and successfully captured him, causing Dou Jiande's army to collapse instantly.
But after the war, Li Shimin did not completely pursue the scattered army. Therefore, when Liu Heimin raised troops again, Dou Jiande's old troops quickly converged on him from all directions.
In just a few months, Liu Heimin not only defeated several Tang generals sent by Li Yuan, but also seized all the territory before Dou Jiande. At the same time, Liu Heimin also received the full support of the northern Turks, posing a great threat to the Tang Dynasty.
Liu Heimin had become a serious threat that the Tang Dynasty could not ignore, and if it was not defeated, the Tang Dynasty's dream of unifying the world could only be empty talk. In order to deal with this threat, Li Yuan had to hand over the heavy responsibility to Li Shimin and send him to lead the army to defeat Liu Heimin.
In the entire Tang Dynasty, only Li Shimin had this qualification and ability. In December 621, Li Shimin ended half a year of life as a prince and once again held the military power.
This battle will undoubtedly deeply affect the future historical trend of the Tang Dynasty. Li Shimin led his army to Zhaozhou and confronted Liu Heimin. Liu Heimin's soldiers fought extremely bravely, and even captured the city of Zhushui at one point, resulting in the death of Li Shimin's general Luo Shixin.
Although Li Shimin later recaptured the city, he paid a huge price.
In the battle with Liu Heimin, Li Shimin gradually understood the strength of the other party and realized that Liu Heimin was not easy to match. Therefore, in the following battle, Li Shimin adopted a defensive-oriented strategy, using the huge resources and sufficient supplies of the Tang Dynasty to launch a protracted war with Liu Heimin.
Although Liu Heimin's morale was high, because Dou Jiande's territory had just been restored, many places had not yet established effective rule, so he was at a disadvantage in terms of grain and grass supply.
Li Shimin's strategy is to defend himself, consume Liu Heimin's grain and grass, and then look for an opportunity to defeat him. In the past two months, no matter how Liu Heimin challenged, Li Shimin always maintained a defensive posture until Liu Heimin's grain and grass were completely exhausted, and the army's morale began to waver.
Li Shimin predicted that Liu Heimin would make a desperate gamble after losing his grain and grass, and lead all the main forces to a decisive battle with the Tang army. For this reason, Li Shimin occupied the upper reaches of the river in advance and cut off the river, in an attempt to use the water to defeat Liu Heimin.
Li Shimin's prediction really came true. On March 26, after Liu Heimin had exhausted all the grain and grass, he led all the army and went all out to decide to fight Li Shimin to the death.
When Liu Heimin's main force crossed the river, Li Shimin led the main force of the Tang army to start a decisive battle with Liu Heimin's army. Just when the fierce battle between the two sides was in full swing, Li Shimin decisively ordered the upstream to open the sluice gate and release water.
As a result, all of Liu Heimin's follow-up reinforcements were washed away by the flood, and Liu Heimin's army was also cut off by the water. In the end, the Tang army won a complete victory, and Liu Heimin only led a few hundred guards to escape.
After the end of the Battle of Laoshui, Liu Heimin did not gather his forces again, but fled directly to the Turks, hoping to seek reinforcements from the Turks and fight the Tang army again. However, during the time when Liu Heimin went to the Turks, Li Shimin had already pacified all of Liu Heimin's territory, and then returned to the court.
Four months later, Liu Heimin actually received Turkic assistance, and made a comeback with Turkic reinforcements, swept Hebei, and defeated the Tang generals. At this time, Li Shimin had already returned to the dynasty, and Liu Heimin was not hindered and occupied a large amount of territory again.
Li Yuan sent people to suppress it many times, but they were all defeated by Liu Heimin. This time, Li Yuan asked the crown prince Li Jiancheng to lead the troops to pacify Liu Heimin, because Li Jiancheng was not a mediocre talent, and as the crown prince, he had always stayed in the center.
With Li Jiancheng's ability, it is more than enough to deal with Liu Heimin. At the same time, the Tang army has always been led by Li Shimin, resulting in Li Jiancheng having almost no military merits, and this time leading the troops also helped to stabilize his position as prince.
Li Jiancheng seized the opportunity to conquer Liu Heimin, and this battle was undoubtedly an excellent way for him to build up his military merits. After all, Liu Heimin had been defeated by Li Shimin before, and his forces were weak, and Li Jiancheng was not a mediocre person, so he was able to deal with such an enemy with ease.
As it turned out, the army led by Li Jiancheng easily overwhelmed Liu Heimin's army, and after several major battles, the land that Liu Heimin had painstakingly recovered fell into the hands of the Tang army again.
In the end, Liu Heimin was killed by his subordinates, and Shandong, Hebei and other places were completely pacified. Although Liu Heimin's rebellion did not shake the foundations of the Tang Dynasty, it completely changed the fate of Li Jiancheng and Li Shimin.
Before the decisive battle, Li Yuan and Li Jiancheng's desire to control Li Shimin was already obvious. Therefore, while they were conquest of Liu Heimin, Li Shimin also deployed his henchmen in Shandong, Hebei and other places, and installed many cronies in the army, making him extremely influential in the lower troops of the Tang Army, even surpassing Li Yuan.
As a result, in the next few years, Shandong, Hebei, Henan and other places, as well as the middle and lower armies of the Tang Dynasty, became Li Shimin's stage, laying the foundation for him and Li Jiancheng to compete for the crown prince.