An Lushan Rebellion in the context of "Shi Chaoyi"

Yan (Chinese: 燕; pinyin: Yān), also known as the Great Yan (Chinese: 大燕; pinyin: Dà Yān), was a dynastic state of China established in 756 by the former Tang general An Lushan, after he rebelled against Emperor Xuanzong of Tang in 755. The state collapsed in 763 with the death of An Lushan's former subordinate Shi Chaoyi (son of Shi Siming), who was the last person to claim the title as emperor of Yan.

Emperor Suzong of Tang (yihai day, 711 – 16 May 762; r. 756 – 762), personal name Li Heng, né Li Sisheng (李嗣升), known as Li Jun (李浚) from 725 to 736, known as Li Yu (李璵) from 736 to 738, known briefly as Li Shao (李紹) in 738, was an emperor of the Chinese Tang dynasty and the son of Emperor Xuanzong.

Suzong ascended the throne after his father fled to Sichuan during the An Lushan Rebellion in 756; Li Heng himself had fled in the opposite direction, to Lingwu, where he was declared emperor by the army. Much of Emperor Suzong's reign was spent in quelling the aforementioned rebellion, which was ultimately put down in 763 during the reign of his son Emperor Daizong.

The jiedushi or jiedu was a regional military governor in imperial China. The title was established in the Tang dynasty and abolished in the Yuan dynasty. The post of jiedushi has been translated as "military commissioner" or "governor", "legate", and "regional commander". Originally introduced in AD 711 to counter external threats, the jiedushi were posts authorized with the supervision of a defense command often encompassing several prefectures, the ability to maintain their own armies, collect taxes and promote and appoint subordinates.

Powerful jiedushi warlords eventually became fanzhen rulers, able to override the power of the central government of Tang. An early example of this was An Lushan, who was appointed jiedushi of three regions, which he used to start the An Lushan Rebellion that abruptly ended the golden age of the Tang dynasty. Even after the difficult suppression of that rebellion, some jiedushi such as the Three Fanzhen of Hebei were allowed to retain their powers due to the weakened state of the court. The jiedushi were one of the primary factors which contributed to the political division of the Five Dynasties and Ten Kingdoms period, a period marked by continuous infighting among rival kingdoms, dynasties, and regional regimes established by the jiedushi.

Yang Guozhong (traditional Chinese: 楊國忠; simplified Chinese: 杨国忠; pinyin: Yáng Guózhōng; Wade–Giles: Yang Kuochung) (died July 15, 756), né Yang Zhao (楊釗), was a Chinese politician who served as principal chancellor of the Tang dynasty from 752 to 756, late in the reign of Emperor Xuanzong. Known in his youth as a gambler and wastrel, Yang rose rapidly to political power after his distant cousin, Yang Yuhuan, became Emperor Xuanzong's favorite consort in 744. His familial ties and skills as a financial administrator helped him navigate the tumultuous court politics of the late 740s and early 750s to become the emperor's leading chancellor in 752. While Yang enjoyed Emperor Xuanzong's trust, his competence as chancellor was questioned and he became entangled in a fierce rivalry with an erstwhile political ally, the general and imperial favorite An Lushan. Yang was blamed for precipitating An's cataclysmic rebellion in 755. In the following year, he forced the Tang army of Geshu Han, then holding favorable defensive positions in Tong Pass, to confront the rebel army, leading to a rout of Tang forces and the fall of the imperial capital, Chang'an. Yang attempted to flee to his base in Chengdu with Emperor Xuanzong, but when the imperial party stopped at Mawei Station in modern Shaanxi, Yang and his family, including Yang Yuhuan, were massacred by imperial guard soldiers who blamed them for the chaos.

The Three Fanzhen of Hebei (Chinese: 河朔三镇; pinyin: Hé shuò sān zhèn) were three regions in what is now Hebei, China governed by powerful jiedushi in the post-An Lushan Rebellion (755-763) Tang dynasty (618–907). After the rebellion, the three regions of Chéngdé (成德), Lúlóng (盧龍) and Wèibó (魏博) were controlled by ex-rebel generals who held substantial territory and forces. Although nominally under the authority of the Tang dynasty, they were functionally independent fanzhen that continued to the end of the Tang dynasty. In the south, however, the court took a much more aggressive stand against such defense commands as Zīqīng (淄青) (mainly in Shandong), Biànsòng (汴宋) (in east Henan), and Huáixī (淮西) (in south Henan), which posed a more immediate and palpable threat to the transportation of strategic grains through the Grand Canal, on which the court depended.

During Emperor Xianzong's reign the northeast region was briefly subdued, but after his death it became independent again. By the reign of Emperor Wenzong, the central government had lost all control over this region. The situation was summed up thus by Tang dynasty's chancellor Niu Sengru: