Chu and Han : Total War mod

In 221 BC, the Qin state unified China by conquering the other six major states and established the Qin dynasty. However, the dynasty lasted 16 years only because its rule was extremely unpopular due to its oppressive policies. In 209 BC, Chen Sheng and Wu Guang started the Dazexiang Uprising to overthrow the Qin dynasty. Although the uprising was crushed, several other rebellions erupted consecutively all around China over the next three years. Many rebel forces claimed to be restoring the former six states, and numerous pretenders to the thrones of the states emerged, resulting in the formation of many insurgent states. In 206 BCE, the last Qin emperor, Ziying, surrendered to Liu Bang and brought an end to the Qin dynasty.

Among the rebel forces, the most powerful one was the Chu kingdom. Xiang Yu, a Chu general, won the support of many other rebel leaders after his victory at the Battle of Julu, and became the de facto leader of all the insurgent forces. After the collapse of the Qin dynasty, Xiang Yu divided the former Qin Empire into the Eighteen Kingdoms, each governed by a vassal king, and gave King Huai II of Chu a more honourable title, "Emperor Yi of Chu". However, the emperor was merely a puppet ruler because power was concentrated in the hands of Xiang Yu. About a year later, Xiang Yu relocated Emperor Yi to Chen County (郴縣; present-day Chenzhou, Hunan) and effectively sent the figurehead emperor into exile. He secretly ordered Ying Bu (King of Jiujiang) to murder Emperor Yi while the emperor was on his way to Chen County.

During the division of the Eighteen Kingdoms, Xiang Yu appointed some former rebel generals as vassal kings even though these generals were subordinates of other lords, who should rightfully be the kings instead. Besides, the Guanzhong region was granted to three surrendered Qin generals even though the land was rightfully Liu Bang's, according to an earlier promise by Emperor Yi. Liu Bang was instead sent to the remote Bashu region (巴蜀; in present-day Sichuan and Chongqing) and was given the title "King of Han" (漢王). Xiang Yu proclaimed himself "Hegemon-King of Western Chu" (西楚霸王) and ruled nine commanderies in the former Liang and Chu territories, with his capital at Pengcheng (彭城; present-day Xuzhou, Jiangsu).