The historiographical term "Eighteen Kingdoms" (十八国) refers to the eighteen feudal states created by Xiang Yu in China in 206 BCE, after the collapse of the Qin dynasty. The details of the feudal division are as follows:
The Eighteen Kingdoms were short-lived: almost immediately rebellion broke out in Qi, after which Tian Rong conquered Jiaodong and Jibei, reuniting the old Qi state. Meanwhile, Xiang Yu had Emperor Yi of Chu and King Han Cheng of Hán killed. Thereafter, Liu Bang of Hàn conquered the lands of the Three Qins, thereby starting the Chu–Han Contention. Following many battles and changing alliances, Hàn defeated Chu and subdued all other kingdoms, where Liu Bang appointed vassal kings while making himself the first Emperor of the Hàn Dynasty in 202 BCE.
^1 Yong, Sai and Zhai were collectively known as the Three Qins because they occupied the area of the former Qin state, better known as Guanzhong.
^2 Jiaodong, Qi and Jibei were collectively known as the Three Qis because they occupied the area of the former Qi state.