There is a poem in Du Fu's "Soldier Carriage Line": "The side court bleeds into seawater, and the Emperor Wu has not stopped thinking about it." "Du Fu did not give us an answer when and where the military disaster described in "Soldier Carriage Line" occurred, but the historical data gave us the answer.
In April of the tenth year of Tianbao, Yang Guozhong ordered XiaoZhongzhong to conquer Nanzhao, the Tang army was defeated in the south of Lushui, Yang Guozhong not only concealed the news of the defeat, but also deceived Tang Xuanzong's army into winning the battle, wanted to attack and reward, and recruited troops again to attack Nanzhao, and finally this war that lasted for three years, the Tang army not only did not win the victory, but also killed more than 200,000 soldiers, Du Fu's "Soldier Carriage Line" describes this tragic border court war.
At the beginning of the seventh century AD, there were six relatively large tribes next to the Erhai Sea in Yunnan, known as the "Six Commandments", of which the MengsheZhao was south of several other tribes, also known as the "Nanzhao", and the Nanzhao was politically closer to the Tang, so the Tang also wanted to support the unification of the Six Edicts of the Nanzhao, which was also to curb the expansion of tubo forces to the southwest of the Tang.
It was not until the reign of Emperor Xuanzong of Tang, with the support of Tang, that Pi Luoge, the king of Nanzhao, finally annexed the remaining five edicts and unified the Erhai region, and under the governance of Pi Luoge, the sphere of influence of the Nanzhao regime also expanded from the Erhai area to today's southern Sichuan, western Guizhou and other regions, maintaining friendly and stable relations with the Tang for decades.
Nanzhao Kingdom
In the twenty-sixth year of the new century, Tang Xuanzong sealed Pi Luoge as the "King of Yunnan", and it is reasonable to say that the relationship between Tang and Nanzhao should be very close and friendly, so why did the relationship between the two sides turn sharp after just a dozen years, to the point where they had to meet each other?
The main reason is because of the political corruption of the Tang Dynasty in the late reign of Tang Xuanzong. In the ninth year of Tianbao, Pi Luoge's son Ge Luofeng took his wife and daughter to Chengdu, passing through the Governor's Mansion of Yao Prefecture in Western Yunnan, and the Governor of Yao Prefecture, Zhang Qiantuo, actually flirted with Ge Luofeng's wife in person, and Ge Luofeng did not want to turn his face to The Tang because of this trivial matter, he initially just thought that even if it was the Tang Dynasty, it was inevitable that there would be negligence and appoint such a treacherous villain.
So Ge Luofeng ordered the general Yang Luofeng to be a special envoy, and went to Chang'an to accuse Zhang Qiantuo of Tang Xuanzong, but at this time, Tang Xuanzong was drunk and mixed with Yang Yuhuan all day, and the important affairs of the dynasty were entrusted to Yang Guozhong, so he did not pay attention to this matter at all, Ge Luofeng was very angry, determined to avenge his wife, personally led a large army to attack the governor's mansion of YaoZhou, killed Zhang Qiantuo, and occupied the area around Yaozhou.
Ge Luo Feng
Ge Luofeng still didn't want to turn his face to Datang at this time, he just wanted to end his grudge with Zhang Qiantuo, these disputes had nothing to do with Datang, just his own dispute with Zhang Qiantuo, and the war should have ended at this point. Although the Tang Dynasty was powerful, it was obviously not worth it to make a big fuss for such an outlaw official as Zhang Qiantuo and Nanzhao, and according to normal practice, the Tang Dynasty should lower the edict to appease Ge Luofeng and restore stability to the border.
However, when Tang officials handled this small dispute on the border, they did their best to keep the situation going and develop the incident into an all-out war with the Nanzhao state. In April of the tenth year of Tianbao, Yang Guozhong's close confidant Jiannan Jiedushi made Xian Yuzhong, at the behest of Yang Guozhong, brazenly send troops to attack the State of Nanzhao, and after Ge Luofeng learned the news, he immediately explained the situation to The Tang and repeatedly expressed to Xian Yuzhong that he was loyal to the Tang, but no matter how Muchao Feng asked for peace, Xian Yuzhong flatly refused to accept it, and when he was cornered, Ge Luofeng could only turn to Tubo.
Tubo and Tang dynasty confrontation for many years, after receiving the nanzhao king's request for help, tubo immediately sent reinforcements and nanzhao joint battle, many times defeated the Tang army, as the prime minister Yang Guozhong saw that his henchmen suffered defeat, and constantly did not want to calm the war, but also added fuel to the fire, Tianbao thirteen years, Jiannan left Li Mi to send 100,000 troops, again to conquer Nanzhao.
The Tang army was stationed on the north bank of the Erhai Sea, and the south bank of the Erhai Sea was the capital of Nanzhao, and Tubo's reinforcements were stationed in the north of the Tang army, and Ge Luofeng led an army to sneak up on the Tang army and attack the Tang army together with the Tubo reinforcements, the Tang army was blocked in Chengchuan, the Tang army led by Li Mi was completely destroyed, Li Mi committed suicide by throwing himself into the river, and the Tang Dynasty was defeated again.
At this point, the Tang Dynasty lost control of Yunnan and other places, and worse, Nanzhao formed an alliance with Tubo and posed a serious threat to the Tang Dynasty in the southwest, but who can blame this? This was not caused by Tang Xuanzong's favored traitor Yang Guozhong, who was self-inflicted.
After the end of the war, Ge Luofeng was still unwilling to completely break with the Tang Dynasty, and he had people set up the "Nanzhao Dehua Monument" to explain to posterity why Nanzhao would break out this war with the Tang Dynasty, hoping that one day when Nanzhao would return to good in the Tang Dynasty, posterity could objectively comment on the war and let the Tang Tianzi know the truth of the war.