The Anshi Rebellion became a turning point in the history of the Tang Dynasty. The division of feudal towns, foreign invasions, and the dictatorship of eunuchs competed with the Niu Li Party.

As a result, it became the internal and external troubles of the Tang Dynasty. In order to end the war as soon as possible, the Tang family named General An Shi as a festival envoy on the spot to appease him.

In order to guard against the rebellion of the generals, they placed festival envoys everywhere. Due to the fact that the Jiedu envoy was in charge of the local military, politics and economy, the whole country was almost semi-independent.

After the war, the number of people in the Kwantung region decreased sharply, the land was largely barren, and the land of Hebei gradually became Hu, and the people were good at martial arts and light literature.

As the border guards were transferred back to quell the unrest, foreign tribes invaded one after another. Tubo occupied Longxi and invaded Guanzhong, and Chang'an fell for a time.

The extortion of the Hui also consumes national strength. The eunuchs were autocratic, Li Fuguo and Cheng Yuanzhen supported the Tang Dynasty as emperor, and the eunuch Yu Chaoen was appointed to lead the forbidden army.

In 779, Tang Dynasty Zong died in these turmoil, and was succeeded by his eldest son, Li Shi, Tang Dezong. In the early days, Tang Dezong was quite able to exert himself and resolutely cut down the feudal towns, and the feudal towns were more in awe of him.

He used Yang Yan to implement the two tax laws, and Liu Yan reformed Caoyun, revised the salt law, and implemented the Changping law to improve finances.

But he was rigid and jealous, and he did not let others know. After the appointment of the treacherous minister Lu Qi in 781, politics became increasingly unsuccessful.

Listen to Lu Qi's slanderous rumors and kill Yang and Liu. Political corruption led to the gradual contempt of the feudal towns, and finally chaos broke out.

In the same year, Chengde Li Baochen died, and his son Li Weiyue was not approved by the Tang family to succeed him, so he united with Wei Botian Yue and Ziqing Li Na to raise troops to rebel.

The Tang dynasty sent Ma Sui and Li Sheng to defeat the rebels, Tian Yue was besieged by the central army in Weizhou, and Li Weiyue was killed by his subordinate Wang Wujun.

On the other hand, after Lu Long Zhu Zhu entered the court, he was succeeded by his younger brother Zhu Tao as Lu Longjie's envoy. Because Lu Long Zhu Tao and Chengde Wang Wujun were dissatisfied with the imperial court, they united with Ziqing Li Na and Huaixi Jiedu to make Li Xilie rebel and jointly elected Zhu Tao as the leader of the alliance.

The Jingyuan army, which was transferred to resist Huaixi, was also dissatisfied with the imperial court's rewards, and the Jingyuan mutiny broke out, and the Tang Emperor fled to Fengtian.

After the Jingyuan army entered Chang'an, they jointly established Zhu Zhu as the emperor and surrounded Fengtian. Li Sheng urgently led the Central Army back to Guanzhong and relieved the siege of Fengtian with Li Huaiguang of the Shuofang Army.

Afterwards, Tang Dezong did not summon Li Huaiguang because of Lu Qi's slander, although Lu Qi was demoted in the end, Li Huaiguang still resented Emperor Tang.

In 784, Tang Dezong adopted Lu Zhen's policy and agreed to the demands of the feudal towns, but only Zhu Zhu refused to pardon them, and abolished the harsh taxes, and the feudal towns submitted one after another.

Zhu Tao and Li Xilie were unwilling to surrender and wooed Li Huaiguang to defect, and Tang Dezong fled to Liangzhou. In the same year, Li Sheng recovered Chang'an, Zhu Zhu was killed by his subordinates when he fled east, Li Huaiguang was also destroyed by Ma Sui and Hun Yang in the following year, and Li Xilie in Huaixi was also killed by his subordinates, so the chaos was calmed down.

However, the Tang dynasty recognized the right to rule the feudal towns, deepening the separatism. Because Tang Dezong did not trust the generals, the forbidden army was transferred to the control of the eunuchs, and the eunuchs were powerful.

In his later years, Tang Dezong appointed the traitor Pei Yanling, and was intimate with eunuchs and corrupt officials, and the country's politics were declining.