The decline of the Tang Dynasty was not caused by a single event, but by a combination of long-term internal weaknesses and external pressures. In general, four major factors led to the fall of the Tang Empire. Among them, the dominance of eunuchs, the rise of regional warlords, and factional struggles within the court were internal causes, while large-scale peasant uprisings served as the decisive external force.
Eunuch Domination and the Weakening of Imperial Power
One of the most destructive factors in the late Tang Dynasty was the unprecedented political power held by eunuchs. From the later years of Emperor Xuanzong’s reign, the long-standing rule that eunuchs should not participate in state affairs was gradually abandoned. Influential eunuchs such as Gao Lishi and Li Fuguo gained control over the imperial guards and even influenced the succession of emperors.
As their power expanded, eunuchs were able to interfere in major state decisions, appoint and dismiss officials, and manipulate military authority. This severely weakened the central government and suppressed capable ministers, leading to constant power struggles between eunuchs and civil officials and undermining effective governance.
Regional Warlords and the Problem of Fanzhen
Another critical cause of Tang’s decline was the emergence of powerful regional military governors known as Jiedushi. Originally established to defend frontier regions, these commanders gradually accumulated both military and administrative authority, especially after the An Lushan Rebellion.
Over time, many Jiedushi became independent warlords, forming semi-autonomous regions known as Fanzhen. These warlords controlled their own armies, collected taxes independently, and frequently clashed with the central court. As a result, the unity of the Tang Empire was seriously threatened, and the authority of the imperial government continued to erode.
Factional Struggles within the Court
Political infighting among court officials further weakened the Tang state. Officials were mainly divided into two groups: the traditional aristocracy and the emerging civilian scholar-officials. Due to differences in background, interests, and political views, these groups formed rival factions.
Rather than focusing on effective governance, factional leaders engaged in prolonged power struggles to suppress their opponents. These internal conflicts disrupted policymaking, reduced administrative efficiency, and further destabilized the already fragile central government.
Peasant Uprisings and Social Collapse
The final and most direct cause of the Tang Dynasty’s collapse was widespread peasant rebellion. In the late Tang period, land concentration became severe, and peasants suffered heavy exploitation by landlords, officials, and eunuchs. Years of warfare and natural disasters worsened living conditions, while taxes remained high.
Under these pressures, large-scale uprisings broke out across the empire. Among them, the Huang Chao Rebellion delivered a devastating blow to the Tang regime. Although the dynasty continued to exist for several decades afterward, its political and military foundations had been irreparably damaged, and the empire gradually descended into chaos and eventual collapse.