July 4, 618. Li Shimin led the Tang army to fight xue ju's troops at Gaoyuan.
Li Shimin analyzed the battle situation and believed that Xue Ju's troops had traveled a long way, lacked food and pay, and would definitely think of a quick battle and a quick decision.
So he ordered the Tang army to occupy Gaoyuan and build fortifications. Wait for work, don't take the initiative.
Unfortunately, during the stalemate between the two sides, Li Shimin suddenly contracted malaria and was bedridden, unable to command the battle.
Li Shimin had to hand over military power to Liu Wenjing and Yin Kaishan, and in the process of handing over military power to them, Li Shimin advised them: "Xue Ju's grain is small, and the soldiers are very tired.
Instead of fighting a protracted war. If they come to challenge, you must be careful not to fight easily. Wait until my illness is a little better, then solve them. ”
However, after the two men walked out of the Marshal's Palace, Yin Kaishan said to Liu Wenjing: "The King of Qin has just contracted an illness and may have lost confidence. That's why we said such things, we should take the opportunity to defeat the enemy army, and we can't leave the trouble to the King of Qin. ”
At the repeated instigation of Yin Kaishan, Liu Wenjing changed the strategy set by Li Shimin.
Liu Wenjing took the initiative to transfer the army out of the fortifications and lined up outside the fortifications. Because the Tang army was strong and strong, Liu Wenjing did not look up to the enemy army very much, so he did not have any defense against the enemy army.
Xue Ju saw that the Tang army took the initiative to come out to fight, so he led the army back to the rear of the Tang army to launch an attack.
The two sides fought in Shallow Water Plains, the Tang army was forced to fight, and because it was the enemy on the stomach and back, the army was in turmoil, and it was not long before it was defeated, the Tang generals Murong Luoju and Li Anyuan were killed, Liu Hongji was captured, and more than half of the soldiers were killed.
When Li Shimin heard the news, he had to drag his sick body to lead the troops to retreat, and Xue Ju took the opportunity to occupy Gao Yuan.
In August 618, someone suggested to Xue Ju that he take advantage of the victory and take Chang'an.
Xue Ju immediately agreed, and while the whole army was ready to attack, Xue Ju suddenly fell seriously ill and died soon after, and Xue Ju's son Xue Rengao (gǎo) had to lead the army to retreat.
The first battle between the Tang army and Xue Ju in the shallow water plains also came to an end.
In 618, Li Shimin ordered the army to "dare to speak out and behead", thus beginning the Second Battle of Shallow Water Plains.
After the Tang army's crushing defeat at the First Battle of Shallow Water Plains, Li Yuan realized that the threat to the Tang and Xue Rengao regimes was enormous.
Therefore, Li Yuan immediately sent people to Liangzhou to woo Li Rail, who had a conflict with Xue Rengao, and let Li Rail harass Xue Rengao behind him. In his letter to Li Rail, Li Yuan intimately referred to Li Rail as "Consort Brother". Li Rail was overjoyed when he received the letter and immediately sent his brother to the Tang Dynasty to pay tribute. Li Yuan made the tribute Li Mao (mào) a general, and also made Li Rail the governor of Liangzhou, the King of Liang.
On August 17, 618, in the first year of Wu De's reign, Li Yuan took Li Shimin as his commander and sent an army to attack Xue Rengao.
After Li Shimin's army reached Gaoyuan, he could not hold out. Xue Rengao sent his troops to meet Zong Luohu, and Zong Luohu repeatedly challenged him, but Li Shimin ignored it.
Li Shimin also ordered those in the army to "behead those who dare to speak out." As a result, Li Shimin's department and Zongluo's department were deadlocked at Gaocheng Castle.
On September 12, Li Yuan sent Dou Lu, the governor of Qin Prefecture, to lead an army to attack Xue Rengao's location, but was defeated by Xue Rengao.
Xue Rengao pursued the Tang army all the way, and finally beat the rabbits with grass and surrounded Li Tang's Jingzhou. The Tang general Liu Gan, with the Jingzhou garrison, was besieged until the grain was exhausted, to the point of boiling the bones of the horse with the wood chips to fill the hunger.
When Li Yuan saw this, he immediately sent Li Shuliang, the King of Changping, to lead troops to relieve the siege of Jingzhou.
Xue Rengao saw that Jingzhou could not be attacked for a long time, and there were reinforcements from Li Tang, so he hyped up the depletion of military food and led the army to retreat.
However, the next day, Xue Rengao sent people to falsely claim to the Tang army that the folding people saw that Xue Rengao could not achieve a big deal, and the city surrendered. Li Shuliang believed it to be true, and actually sent Liu Gan to lead troops to receive it.
At this time, Xue Rengao led his troops to ambush in the Hundred Mile River, and when the Tang army passed by, Xue Rengao suddenly attacked, the Tang army collapsed, and Liu Gan was also captured.
Xue Rengao once again led his troops to surround Jingzhou, Li Shuliang was terrified, and took out a large amount of money to reward the soldiers, and the city of Jingzhou was heavily defended, containing a large number of Xue Rengao's troops.
Although the tang army's war along the way was not very smooth, it also relieved a lot of pressure for Li Shimin.
On November 7, Li Shimin and Zong Luohu had been deadlocked for more than sixty days, Zong Luohu's grain and salary had been exhausted, and the morale of the army had been greatly problematic. Zong Luo's general Liang Hulang ,内史令翟長sun , and Xue Rengao 's brother-in-law Zhong Juqiu ( 钟俱仇 ) led their troops to surrender to the Tang Dynasty.
Li Shimin asked Liang Shi, the commander of the march, to take some of his soldiers to deploy in the shallow water to attract Zong Luo's army.
Zong Luo saw that the Tang army was finally willing to go out of the city to fight, and was overjoyed, and immediately launched an attack on the Tang army's position with elite troops.
Liang Shi was not an easy man, he relied on the favorable terrain he occupied, and led the Tang army to desperately resist Zong Luohu's many attacks, but they did not return.
As a result, Zong Luohu cut off the water source of the Tang army led by Liang Shi.
However, even if the water source was cut off, the Tang army still held on to the danger.
As the saying goes, one drum blows, then declines, three exhausts. After many days of fighting, zongluo's army was demoralized.
Li Shimin immediately sent Pang Yu to lead some troops to line up in the western part of the shallow water plains.
Zong Luohu "held himself up" and commanded the whole army to attack Pang Yubu.
Although Pang Yu struggled to resist, he was outnumbered and was about to lose.
At this time, Li Shimin took the main force of the Tang army around the back of Zong Luo's troops, took it by surprise, and launched an attack.
Zong Luo was horrified and immediately turned around to attack, but the dispatch of the large army was so easy. Under the leadership of Li Shimin, the Tang army was greatly boosted and fought to the death. After the defeat of zongluo's army, the soldiers scattered and fled, and countless people fell into the ravines of the river.
Li Shimin ordered 2,000 fine horses and prepared to pursue. Dou Lu advised him to be cautious and careful before making plans. Li Shimin ignored it and resolutely wanted to take advantage of the victory to pursue and cut the grass and remove the roots.
Li Shimin pursued all the way to the south of the city, and Xue Rengao's troops fought at the edge of jingshui.
Soon, Xue Jun's general defected and surrendered to the Tang army.
Xue Rengao was frightened by this backstab and led his troops into the city to defend.
In the evening, the main force of the Tang army arrived and surrounded the city of Folding Mountain. In the middle of the night, Xue Rengao's soldiers fled over the city wall.
On November 8, 618, Xue Rengao surrendered.
Xue Rengao was escorted to Chang'an and beheaded. Xue Qin perished.
The reason for the success of this second Battle of Shallow Water Plains was that Li Shimin seized on the weakness of Xue Jun's inconvenient transportation and inability to replenish grain and grass in time. Jianbi Qingye successfully drained Xue Junzong's throat to the point where people were trapped and tired.
After the enemy army was exhausted, he sent Liang Shi to lead a small number of Tang troops to deplete the military strength of Zong Luo's throat. One last resort.
This battle was only three months after the first Battle of Shallow Water Plains, and the Tang army was humiliated under the leadership of Li Shimin.