[Why] When the early Qing pacified the south, it enfeoffed three surrendered Han generals Wu Sangui, Shang Kexi, and Geng Jingzhong as vassal kings, but their three-vassal power grew large and threatened the center. Emperor Kangxi resolved to withdraw the vassals and finally solve this hidden danger. [What] Wu Sangui raised troops against Qing in Yunnan and proclaimed himself King of Zhou. Geng Jingzhong of Fujian and Shang Zhixin of Guangdong responded in turn. The rebellion swept half the realm for eight years. Kangxi mobilized Eight Banners and Green Standard troops and finally smashed the rebellion definitively at the fall of Kunming. [Who] Emperor Kangxi Xuanye was the young strategic commander facing a life-and-death great test, displaying extraordinary political will. Wu Sangui was a fickle political opportunist who from opening the pass to welcome Qing to raising arms against Qing finally lost reputation and life. [How] The complete pacification of the Three Feudatories marked the Qing center's final absolute grasp of all Han land in the country, ending the local-fragmentation tradition since the late Ming. It laid the key political and military foundation for the opening of the Kangxi-Qianlong prosperity.
Why
The historic event of Three Feudatories Revolt represents a key developmental peak of the Huaxia dynastic system. The decisive military-political victory consolidating Qing central rule over all Han China. By establishing this moral or administrative benchmark, it continues to shape the structural and philosophical fabric of ancient Chinese statecraft.