"Five hundred miles of Dianchi Lake, rushing to the bottom of the eyes, draped in the shore, happy and vast and boundless", "Thousands of years of past events, attention to the heart, the wine is empty, sighing and rolling heroes who are there", "Look at the East Dragon God Jun, West Qi Lingyi, north winding, South Xiang Miaosu", "Want Han Xi Lou Ship, Tang Biao Iron Pillar, Song Wielding Jade Axe, Yuan Cross Ge Sac", this is a famous long line in the Grand View Tower of Kunming, Yunnan Province. This couplet was made by the famous Qing Dynasty scholar Sun Qiweng, who made a concise summary and review of the history, culture and natural scenery of Yunnan, and has always been known as a divine work in the works of ancient Yang lian.
In this couplet, many historical allusions related to Yunnan are quoted, and "Song Wielding the Jade Axe" is one of them. In 960, Zhao Kuangyin launched the Chen Qiao Mutiny, usurping the Later Zhou Dynasty in one fell swoop and establishing the Great Song Dynasty. Since Later Zhou was only a small divided country in the north, its land area was extremely limited, and there were still many small divided states and warlords left over from the Yellow River in the north and south of the Great River, so after Zhao Kuangyin opened the country, he immediately dispatched troops and generals to carry out a large-scale unification war.
In the second year of Qiande (964), Zhao Kuangyin sent the general Wang Quanbin to lead a large army to attack Houshu, which was occupying Sichuan. The Later Shu monarch Meng Chang could not withstand the onslaught of the Song army and was forced to surrender, and Sichuan was incorporated into the territory of the Song Dynasty. After a detailed survey of the geographical situation of the mountains and rivers throughout Sichuan, Wang Quanbin found that the Dali state that occupied Yunnan bordered Sichuan, so he wanted to take advantage of the victory and enter the army, destroy the Dali state with a single blow, and take Yunnan into the Song Dynasty.
The Dian Zai Ji records that "Wang Quanbin, who was both peaceful and Shu, wanted to take Dian because of his military might in order to advance on the top", and presented the map of the two provinces of Sichuan and Yunnan to Zhao Kuangyin, the grandfather of the Song Dynasty. Who knew that Zhao Kuangyin looked at the map and groaned for a long time, and with a jade axe he was playing with in his hand, he drew a line along the Dadu River at the junction of the Song Dynasty and the Dali State, and said: "In addition, I have it." The Yancheng Chronicle also records that "since Yunnan has not been able to pass through the Central Plains". Since then, neither Zhao Kuangyin himself nor the Song Dynasty army has dared to step into Yunnan since then.
Zhao Kuangyin is a generation of heroes with excellent literary ability and martial arts, who has experienced hundreds of battles and repeatedly defeated strong enemies, what kind of enemy has not seen, why does he dare not step into Yunnan? What exactly was Zhao Kuangyin afraid of, what was he worried about? It turned out that Zhao Kuangyin did this, and he really had some reasoning, "Taizu Jian Tang's calamity was based on Nanzhao", nanzhao state is the predecessor of Dali state, tang dynasty because it failed to properly handle its relationship with it, suffered a big loss for this.
During the Tang Dynasty, the Nanzhao State of Yunnan was once a vassal state of the Tang Dynasty and belonged to the jurisdiction of the Tang Dynasty. However, the Nanzhao State was nearly three thousand miles away from the center of Tang Dynasty rule, and the Tang Dynasty was really beyond its reach. In addition, the humid, hot and rainy temperature in the territory of Nanzhao, the mountains and mountains, the crisscrossing of rivers, and the climatic and geographical characteristics made it difficult for the Central Plains army to adapt, so it was not easy for the Tang Dynasty to truly maintain its rule over Nanzhao.
In the ninth year of Tang Xuanzong Tianbao (750), the Tang Dynasty's Yunnan Taishou Zhang Qiantuo had a fierce military conflict with the Nanzhao king Ge Luofeng, and the two sides fought a big fight, and the Tang Dynasty and Nanzhao War began, known in history as the "Tianbao War". Yang Guozhong, the reigning minister at the time, in order to consolidate his position in order to establish a meritorious name, vigorously instigated Tang Xuanzong to send a large-scale army into Yunnan, hoping to completely destroy Nanzhao.
As mentioned above, although the Tang Dynasty army was known for its good battles, but wading through mountains and rivers for thousands of miles and long-distance raids, coupled with the inability to adapt to the climatic and geographical characteristics of Yunnan, the Nanzhao military and civilians fought desperately for self-protection, which eventually led to the Tang Dynasty suffering three major defeats in succession, with heavy casualties, "several hundred thousand people died before and after", making the Tang Dynasty's military strength suffer a heavy blow, which was regarded as the starting point of the Decline of the Tang Dynasty.
In view of this, Zhao Kuangyin, in order to avoid repeating the mistakes of the Tang Dynasty, took the initiative to give up the inclusion of Yunnan in the territory of the Song Dynasty. But history has mixed opinions of his move, with some seeing it as a sign of his generosity and benevolence, and his refusal to risk the lives of soldiers fearlessly. Some people also say that he is cowardly and conservative, irresponsible to the country, resulting in the Song Dynasty becoming a small and incomplete court, which is still difficult to determine.
References: "YanCheng Chronicle", "Chronicle of the Lineage Since Jianyan", "Dian Zai", "Old Book of Tang"