Chapter 21 Section 3 Decline After Prosperity: The Territory After the Mid-Tang Dynasty

In the 14th year of Tianbao (755 A.D.), the Anshi Rebellion broke out, and the Tang Dynasty tried its best to deal with it, and the western border was seized by Tubo (bobo).By the time the rebellion subsided in the first year of Guangde (763 A.D.), Tupan now owned Mount Long, Liupan Mountain, the west of the Yellow River, and the west of the Sichuan Basin.At the beginning, some administrative districts in the Hexi Corridor were still guarded by local officials of the Tang Dynasty, but soon they fell completely under the control of Tubo.The whole province of southwest Yunnan, southern Sichuan and western Guizhou were all owned by Nanzhao. The west and west Guangxi are no longer under the jurisdiction of the Tang Dynasty.With the rise and expansion of the Bohai State, the territory of Northeast China has also shrunk to what is now central Liaoning.

In the second year of Dazhong (848 A.D.), Zhang Yichao, a native of Shazhou (where the government is located in the southwest of Dunhuang City, Gansu today), expelled the Tubo guards and recovered Shazhou.Later, Guazhou (where the government is located in the southeast of Anxi County, Gansu), Suzhou (where the government is now Jiuquan City, Gansu), and Ganzhou (where the government is now Zhangye City, Gansu).By the fifth year of Dazhong, Zhang Yichao led the 11 states of Sha, Gua, Yi, Xi, Gan, Su, Lan, Shan, He, Min, and Kuo into the Tang Dynasty.In the three years before this, the Tang Dynasty had recovered the three prefectures of Qin, Yuan, and Anle.In this way, the western territory of the Tang Dynasty was restored to the present-day Turpan region of Xinjiang, and the Hexi Corridor was connected with Longdong and Guanzhong.

However, due to the decline of the national power of the Tang Dynasty, it was beyond reach for the frontier.After the Huangchao Uprising broke out in the second year of Qianfu (875 AD), it became even more impossible to control Hexi.The strength of the local Han people was limited, and the land in Longyou and Hexi was successively taken away by Tubo and Huihe. Only Gua and Shazhou were always occupied by the Han people, hanging alone outside the territory of the Tang Dynasty.Later, the Cao regime replaced the Zhang regime, and it was not until the Northern Song Dynasty that it was destroyed in Xixia.

During the Five Dynasties, the territory of the Central Plains Dynasty continued to shrink, and the northern Khitan (later Liao) expanded southward.In the Later Tang Dynasty (923-936 A.D.), Khitan occupied Yingzhou (present-day Chaoyang City and Jinzhou City, Liaoning) and Pingzhou (present-day lower reaches of Luanhe River, Hebei Province).In the first year of Tianfu in the Later Jin Dynasty (936 A.D.), Shi Jingtang set up 16 prefectures centered on Youzhou (the seat of the government today in Beijing) and Yunzhou (the seat of the government in today’s Datong City, Shanxi) (known in history as "Sixteen States of Yanyun") or "Youyun Sixteen States") ceded to Khitan.Among them, the southernmost Yingzhou and Moerzhou were taken back by the Later Zhou Dynasty in the sixth year of Xiande (959 AD), so the two sides took the Baigou (now Juma River) line as the boundary.

In the third year of Tianyou (AD 906) at the end of the Tang Dynasty, Qu Chengmei, a local tyrant in Jiaozhou (now Hanoi, Vietnam), expelled the local officials of the Tang Dynasty and claimed to be the Jiedushi of Jinghai.At the beginning of the Five Dynasties, the Southern Han regime, which occupied Lingnan, sent troops twice to cancel the Jinghai Jiedushi and restore Jiaozhou, but was soon driven away by the locals. In 939 (the fourth year of Tianfu in the later Jin Dynasty and the 12th year of the Southern Han Dynasty), Jiaozhou people expelled the officials of the Southern Han Dynasty again, and Wu Quan became king, and Vietnam broke away from China.Although it still accepted the title of the Chinese dynasty in the future, it actually gradually became an independent country.