On this day 381 years ago, on May 27, 1644 (April 22, 1644 lunar calendar), the Battle of Shanhaiguan broke out. On May 27, 1644, the Qing army arrived at Shanhaiguan, Wu Sangui switched on the switch to welcome the army and entered the customs. On April 25, 1644, the Dashun army invaded Beijing. On May 15, Wu Sangui reported that Shanhaiguan had attacked Dashun army to Beijing. On May 18, Li Zicheng and Liu Zongmin led the Dashun army to invade the capital, and the army pointed directly at Shanhaiguan. On May 26, the Dashun army arrived at Shanhaiguan and formed a siege of Wu Sangui and began to attack Shanhaiguan. On May 27, the Qing army arrived and attacked at noon, and the Dashun army was defeated. On June 3, Li Zicheng held a ceremony to proclaim himself emperor in the city of Beijing and left Beijing early the next morning. The battle of Shanhaiguan, which was of considerable importance in Chinese history, confirmed whether the Great Shun or the Qing Dynasty came to rule China, and had a profound impact on Chinese history. The fall of the capital and the suicide of the emperor marked the demise of the Ming Empire. The Great Shun Army controlled the entire Yellow River Basin and parts of the Yangtze River Basin. The ruling areas included Shaanxi, Ningxia, Gansu, Qinghai, Shanxi, Shandong, Henan, Hebei, Beijing, Tianjin, and parts of Hubei, Jiangsu and Anhui. The four major forces in China at that time were: Li Zicheng's Dashun regime, the Qing regime occupying the eastern part of Liaoning, the Nanming regime, which controlled half of the rivers and mountains south of the Jianghuai River, and the Daxi regime of Zhang Xianzhong, which was entering Shu. From the situation at that time, Da Shun was the most likely regime to unify the whole country. Its huge military strength was enough to deter the other three major forces. The complete bureaucracy of the central government of the empire that took over from Beijing could be used to quickly stabilize the domestic situation. However, the ensuing Battle of Shanhaiguan, the first battle between the Qing and Da Shun armies, changed the fate of Da Shun and also changed the fate of China. From Li Zicheng's entry to Beijing to his departure from Beijing, in just 40 days, Da Shun's advantage quickly turned into the advantage of the Qing Dynasty. The Battle of Shanhaiguan in the late Ming Dynasty was a decisive battle related to the fate of the Chinese nation. Although it lasted only two days, its impact on China lasted for nearly 300 years. It was this war that caused the Manchu Tartars to gain power, and the legacy has not been eliminated until today. The situation at that time was that Li Zicheng had captured Beijing, Wu Sangui was guarding Shanhaiguan, and the Eight Banners soldiers were waiting for an opportunity outside the customs. The three forces were hostile to each other. Among these three forces, the Eight Banners soldiers were the strongest, Li Zicheng's peasant uprising army was second, and Wu Sangui was the weakest, but the most critical party, because Shanhaiguan was the barrier to enter the customs, and the gains and losses of Shanhaiguan would determine which side of the balance of history was tilted. After Chongzhen hanged Coal Mountain, Wu Sangui chose to take refuge in Li Zicheng. On the way to Beijing, he was shocked to hear that his "dream lover" Chen Yuanyuan had been snatched away by Li Zicheng's general Liu Zongmin, so he "rushed to the crown and became a beauty", led his troops back to Shanhaiguan, and turned to Manqing instead. Li Zicheng led the peasant army in pursuit, encircling the Shanhaiguan, and a big war was triggered, and the incentive was almost ridiculous, it was for the prostitute Chen Yuanyuan! The war was very tragic, the corpses of both sides were everywhere, and the blood was flowing into rivers. Wu Sangui's Ningyuan iron cavalry was known as the elite of the Ming Dynasty. In the end, it could not stop the bravery of the king's army and showed a trend of rout. Wu Sangui hurriedly fought to break through and took the Manqing Tartar into the city. He begged several times to send troops, but Dorgon refused. When the king's army and the Ningyuan iron cavalry were both casualties, they came out to pick up the cheap. The king's army was caught off guard, and despite their efforts, they were still defeated. Li Zicheng returned to Beijing and was furious. He beheaded Wu Sangui's father's family and left the city. Beijing, the capital of the Ming Dynasty, was also stolen by the tartar, and the ancient capital under the setting sun seemed to be stained with blood. The outcome of the Shanhaiguan War was a profound disaster for the Chinese nation. Reflecting on this war and learning from it is undoubtedly of great practical significance. There are many reasons for Li Zicheng's failure, the most important one is that the law is not strict, there is a loss of popularity, the king's army in Beijing to plunder the Ming Dynasty officials' property, causing people to be distracted, is a major mistake, and Liu Zongmin forcefully robbed Chen Yuanyuan, but also forced Wu Sangui, the king's defeat on the surface was defeated by the military, but in fact it was defeated by politics. King Chuang is recognized as a rare military genius, but he lacks long-term plans and does not know how to win over the noble family. Such a peasant regime will not last long. There were two reasons why Wu Sangui surrendered to the Qing Dynasty: one was that Chen Yuanyuan was robbed, and the other was that his father was handcuffed and looted. From the perspective of the battlefield performance, it was more reliable to "rush the crown and anger into beauty". Wu Sangui had long ignored his father's life and death. Since the moment Wu Sangui broke with Li Zicheng, his father had already died. Wu Sangui's offering of customs was of course a traitorous act, but it should be seen that Li Zicheng's political missteps were the cause. If the king went to Beijing to restrain his subordinates, history would be another outcome. The army of the king and the Ningyuan iron cavalry were the most effective troops of the Han army at that time. The army of the king was about 100,000, and the Ningyuan iron cavalry was 30,000. If they joined forces, not only could they hold the Shanhaiguan, but even if they fought against the eight-flag soldiers, the chances of winning were also very high. Unfortunately, for the sake of money and beautiful women, the two most effective troops of the Han army fought to the death before the customs, burying the great rivers and mountains. It is really a tragedy of the times! At the moment of national danger, internal struggles for personal interests await the fate of this nation. Today, Xiongguan still stands, as if reminding people not to forget the history written in blood! Comments: The Battle of Shanhaiguan is a battle of national destruction. When the dynasty changes, there are unpredictable circumstances.