The kingdom was named after the state of Qi (11th century BC – 221 BC), a great power during the Warring States period that was later annexed by the Qin during its unification of China. In 206 BC, Xiang Yu divided the Qin empire into Eighteen Kingdoms. Three of them – Qi, Jiaodong and Jibei – were founded on Qi territories and were ruled by the former state's aristocrats. In 203 BC, the region was conquered by Han Xin, a prominent military general serving under Liu Bang, the later Emperor Gaozu of Han dynasty. Han Xin was briefly granted the title "King of Qi", but was later offered Chu instead.