On September 2, 1861, Emperor Xianfeng of the Qing dynasty died at the Chengde Mountain Resort, leaving the imperial throne to a five-year-old boy. The child's mother, a former concubine who had entered the Forbidden City at sixteen and risen to second rank in the imperial hierarchy, moved immediately. Within months she had outmaneuvered the eight regents the emperor had appointed, allied with his principal wife Empress Dowager Ci'an, and declared herself co-regent. She would not fully relinquish power until her death in 1908.

Cixi — Empress Dowager, the Western title given to her by foreign diplomats who had no adequate word for what she was — governed China through three emperors, two of whom she controlled entirely and one of whom she placed under house arrest when he attempted to govern independently. She was not, by Qing law, permitted to rule. She was a woman. She invented a series of fictions — the emperor's illness, the emperor's youth, the emperor's need for guidance — that allowed her to govern for decades while technically occupying a position that had no formal power.

She modernized China's military, suppressed internal rebellions that would have fragmented the empire, navigated the predatory treaty system imposed by European powers with a combination of accommodation and strategic resistance, and oversaw the period of "self-strengthening" that introduced industrial technology to China. She also suppressed the Hundred Days' Reform in 1898, imprisoning the reformers and placing the Guangxu Emperor under arrest — a decision Western historians have used to characterize her as reactionary, while often omitting that the reformers' plans would have ended her power entirely.

She died on November 15, 1908, the day after the Guangxu Emperor died — the circumstances of whose death remain contested.