837. The Tang-Tibetan War and the Alliance

However, the fall of the Ka family did not end the military strife between the Tang and Tibetans, and the Tubo continued to wage a tug-of-war with the Tang Dynasty in the three key regions of the Western Regions, Hexi, and Nanzhao. In Central Asia and the Western Regions, the Tibetans united with the Great Food and Turkic tribes to confront the Tang Dynasty in an attempt to control the Silk Road.

In 751 AD, the Tang general Gao Xianzhi and the Great Food Army fought a famous battle of great historical significance in the history of Sino-Western transportation and cultural relations at Hengros (present-day Zhambyl in southeast Kazakhstan), the Tang Dynasty withdrew from western Central Asia, and the Abbasid Dynasty of the Great Food was revitalized, and its capital Baghdad (now the capital of Iraq) began the Islamization of Central Asia, and the Tang Dynasty embarked on a more tortuous path.

In 755, An Lushan rebelled against the Tang Dynasty, shaking the weakened foundation of the Tang Dynasty. The Tang Dynasty dispatched troops to quell the rebellion, and Tubo took advantage of the situation to attack, collecting the departments of Dangxiang, Bailan, Shatuo, and Tuyuhun, and pressing into the interior of the Tang Dynasty.

In the first year of Zong Guangde of the Tang Dynasty, in 763 A.D., in July, Tubo invaded the Great Earthquake Pass, trapping Lan, Kuo, He, Shan, Tao, Min, Qin, Cheng, Wei and other prefectures, and took the land of Hexi and Longyou.

"Zizhi Tongjian" recorded: "Since the Tang Dynasty was Gaozu Wude, it opened up the border, and even the Western Regions were placed in the governors, prefectures, prefectures and counties. In the Kaiyuan Dynasty, Shuofang, Longyou, Hexi, Anxi, and Beiting were placed to unify them, and Ding Zhuang of Shandong Province was the pawn, and the silk was the military fund, and the fields were opened, and the grain was supplied, and the supervisors and herdsmen were set up, and the cattle and horses were raised, and the military city was in the army, and they looked at each other for thousands of miles. and An Lushan, the elite of the border soldiers were all recruited and sent to help, which was called the line camp, and the soldiers left were weak, and the Tibetan and party departments invaded one after another; In the past few years, dozens of states in the northwest have been lost, from the west of Fengxiang and the north of Fenzhou, all occupied by various departments. ”

In the Western Regions, due to the withdrawal of the Tang Dynasty, the southern part of the Tianshan Mountains was controlled by Tibet, and the tribal peoples originally under the jurisdiction of the Tang Dynasty successively surrendered to Tibet. The Tang defenders who remained in the Western Regions could only rely on the eastern Tianshan Mountains to survive through the "Uighur Road" in the Orkhon River valley in Mobei. As a result, the Uighurs strengthened their position, and the eastern and northeastern regions of the Tien Shan Mountains, centered on Beiting and Xizhou (Turpan), entered the Uighur sphere of influence, and the Pamir to the southern Western Regions and Hexi became the territory of Tibet, while the northern western provinces, including Yanqi and Qiuzi, became buffer zones or contested areas between the two. The Tibetans lost the battle with the Uighurs in 789~792 for the Northern Court, thus laying the foundation for the Uighurs to gain a foothold in the Western Regions.

In the Nanzhao region, the painstaking management of the Tang Dynasty was also in vain. During the Songtsen Gampo period, the Tibetans had extended their military power into the Erhai region of Yunnan, and the five edicts that divided the region were all under the control of the Tibetans, and only the Southern Zhao maintained good international relations with the Tang Dynasty. The Tang Dynasty had always sent troops to support the unification of Nanzhao and the struggle against Tibet.

In 738, the Tang Dynasty named Pi Luoge, the king of Nanzhao, who had unified the six edicts, as the king of Yunnan, the chief of the southwest, and the prince of the state of Yue. Nanzhao played a very active role in the Tang Dynasty's battle against the invasion of Tibet.

In 751 AD, Zhang Qiantuo, the governor of the Tang Dynasty stationed in Nanzhao, was dizzy, and often took advantage of the situation to rape the wife and daughter of the king of Nanzhao, causing resentment and was killed by Luo Feng, the king of Nanzhao. You see, another war caused by "sexual desire between men and women".

In the first year of Guangde, in 763 AD, the eastward invasion of the Tubo army also captured Chang'an, forcing the Tang Dynasty Emperor to flee Shaanzhou (Sanmenxia, Henan) in a hurry. Stayed for 15 days and led the troops to retreat westward.

In 842 A.D., the last Tibetan Zampu Dharma was stabbed to death by a monk because of the destruction of the Buddha, and the Tibetan nobles were divided into two factions, one supported the widow of the princess of Dharma, Wo Song (meaning light protection), and the other supported the queen to buy the beggar's son Yongdan (meaning Mu Jian), and the two factions competed. This struggle also had a direct impact on the Helong region under Tibetan rule. Luomenchuan (Wushan, Gansu) fought fiercely with the envoy Shang Wanwen and the Shanzhou Jiedu envoy, and the movement against the rule of Tibet in various places also continued to rise. The slave uprisings in the Tibetan region were even more ferocious, they killed nobles, dug up the tombs of the kings, and shook the foundation of the Tubo Dynasty. The slave households under the Tubo subordinates in the Helong area also formed the Wen Late Army, and the enslaved Han people in the Helong area returned to the Tang Dynasty one after another.

In 848 A.D., Zhang Yichao, a native of Shazhou, led the people to revolt, and the Tubo guards of Shazhou fled westward.

In 849, the three prefectures of Tubo Qin, Yuan, Anle and the seven guards under the jurisdiction of Yuanzhou, including Shimen, Yizang, Zhengsheng, Shixia, Mujing, Muxia and Liupan, will descend to the Tang Dynasty.

In 851, Zhang Yichao returned to the Tang Dynasty with books from 11 prefectures, including Gua, Sha, Yi (Hami), Su, Shan, Gan, He, Xi, Lan, Min, and Kuo. The Tang people of Helong "untie the beard and wear the crown belt", cheering. The Tang Dynasty then placed the Guiyi Army in Shazhou, with Zhang Yichao as the envoy of the world, ending the history of Tubo's expansion and rule.

However, the war between Tang and Fan did not affect the exchanges between the two sides, and the de facto courtesy between them has been changed to the courtesy of uncles and nephews. Along with the frequent wars between the Tang and Tibetan sides, there were also alliances and border demarcations.

According to historical records, in the more than 100 years from 706 to 822, there were as many as seven important alliances between the Tang and Tibetan sides.

The first time was in the second year of Li Xian Shenlong (706) of Tang Zhongzong, and it was bounded by the Yellow River. and the princess of Jincheng married Tubo Zampu (709), Tubo bribed Yang Ju, the governor of Shanzhou, and asked the emperor to take Hexi Jiuqu as the princess of Jincheng Tang Mudi. Tang Zhongzong Xu Zhi. Jiuqu, water licorice fertilizer, suitable for animal husbandry, and close to the Tang realm, Tubo crossed the Yellow River to build bridges and build cities, and set up Dushan, Jiuqu two armies, so that the Tang army has no danger to defend, often plundered.

In 714, the Tibetans demanded a new demarcation alliance and agreed with the Tang Dynasty to meet at Heyuan (southeast of Xining, Qinghai). Before the alliance was decided, the leader of the Tubo army, Kun Dayan, attacked Tang Lintao with 100,000 troops, and plundered Lan and Weijian horses. The meeting could not be held.

The second alliance of Tang Fan was in the twenty-second year of the reign of Emperor Xuanzong of Tang Dynasty (734). In 729, the Tang Dynasty conquered the stone fort city (south of Huangyuan, Qinghai) established by Tubo. The following year, Tubo asked for peace, and the Tang Dynasty promised to meet the alliance. In 734, the two sides made an alliance and demarcated the boundary at Chiling (Riyue Mountain in the west of Heyuan).

The third meeting was in the first year of Tang Suzong Zhide (756, the Tianbao year also accounted for a part), and the location was the Honglu Temple in Chang'an, Tang Dynasty.

The fourth meeting was held in the first year of Zong Yongtai of the Tang Dynasty (765), also in the capital Chang'an, in the Xingtang Temple.

The fifth time in the fourth year of the establishment of Tang Dezong (783), the second year of the construction of the two sides (781) determined to Helan Mountain as the boundary. The following year, the alliance failed. In the first month of 783, the two sides allied in Qingshui (Qingshuixi, Gansu).

The sixth time was the third year of Dezong Zhenyuan (787), the two sides allied in Pingliang, and this alliance was robbed by Tubo.

The seventh time was in the second year of Changqing (822) of Tang Muzong, which was allied in Chang'an and Lhasa respectively, and erected a monument inscription as evidence. The monument of the Tang Fan Changqing League in Lhasa still exists today!