The province (州 zhōu) was the highest level of regional administration in Han China. It grouped several commanderies under a single overseer—first the Inspector, and in the late Han often the Governor—and became the main building block of warlord and kingdom territory.
Han provinces
The Eastern Han had thirteen provinces (e.g. Ji Province 冀州, Yu Province 豫州, Yi Province 益州, Jing Province 荆州). As the court weakened, provincial officeholders kept their armies and taxes and turned provinces into power bases. Yuan Shao dominated Ji and other northern provinces; Cao Cao built his power from Yan and Yu; Liu Bei took Yi Province; Sun Quan held Jiangdong. The Three Kingdoms were in large part defined by which provinces each side controlled.
In this wiki
Location and faction articles refer to provinces where relevant; character articles often give a figure’s native province or the provinces they governed or campaigned in.