An Lushan Rebellion

The An Lushan Rebellion was a civil war fought in China from 755 to 763 after the frontier general An Lushan rose against the Tang dynasty emperor Xuanzong and declared himself ruler of a rival Yan dynasty. Rebel forces captured both Tang capitals, Luoyang and Chang'an, driving Xuanzong into exile and forcing his abdication in favor of his son, while An Lushan himself was murdered by his own son in 757 amid infighting among the rebel leadership. The prolonged fighting devastated much of northern China, disrupted the empire's census and tax base so severely that later population records show a catastrophic decline across the affected regions, and the Tang court only regained the upper hand with military help from the Uyghur Khaganate. Although the Tang dynasty was formally restored by 763, the rebellion permanently weakened central authority, leaving regional military governors known as jiedushi in effective control of much of the empire for the remainder of the dynasty.