Editing Chu–Han Contention (section)

== Background ==
{{further|History of the Han dynasty}}
Towards the end of the [[Warring States period]], the western [[ancient Chinese states|state]] of [[Qin (state)|Qin]] conquered the [[Seven Warring States|other six states]]{{snd}}[[Han (Warring States)|Han]], [[Zhao (state)|Zhao]], [[Yan (state)|Yan]], [[Wei (state)|Wei]], [[Chu (state)|Chu]] and [[Qi (state)|Qi]]{{snd}}and [[Qin's wars of unification|unified China]] under the [[Qin dynasty]] in 221&nbsp;BCE, and [[King Zheng of Qin]] declared himself the First [[Emperor of China]]. After his untimely death during the [[Qin Shi Huang's imperial tours# Fifth trip|fifth imperial tour]] in 210&nbsp;BCE, the chief eunuch [[Zhao Gao]] conspired with chancellor [[Li Si]] to install the incompetent [[Qin Er Shi|Prince Huhai]] as the new emperor, [[forced suicide|forcing the suicide]] of the heir apparent [[Fusu]] and [[purge|purging]] anyone deemed disobedient in the Qin court. Due to Huhai's corrupt rule, [[Chen Sheng Wu Guang uprising|a massive uprising]] led by [[Chen Sheng]] and [[Wu Guang]] broke out in Dazexiang (modern day [[Yongqiao, Suzhou|Yongqiao District]], [[Anhui]]) in 209&nbsp;BC, and lasted five months until Qin forces finally managed to crush the rebellion.

Although the Dazexiang uprising had failed, other rebellions erupted consecutively over the next three years. The leaders of these rebellions were either [[pretender]]s to the thrones of the former six states conquered by Qin, their supporters, or simply opportunists who wanted to exploit the chaos. Among them, the most notable one was [[Xiang Yu]], a Chu aristocrat descended from a family of generals, who wanted to revive the Chu state with the exiled [[Emperor Yi of Chu|King Huai II]] as its nominal ruler, and reverse China back to the political order of a pre-Qin [[federacy]]. Xiang Yu initially followed the rebellion of his uncle [[Xiang Liang]], and took over the command after the latter was [[killed in action]] in 208&nbsp;BC. He led an outnumbered Chu forces to victory over Qin main forces at the [[Battle of Julu]], and after the battle controlled nine [[Commandery (China)|commanderies]] in the former [[Liang (state)|Liang]] and Chu territories, with the capital at Pengcheng ({{zhi|c=彭城}}; present-day [[Xuzhou]], Jiangsu).

In the meantime, [[Liu Bang]], another notable rebel leader who had initially joined Xiang Yu, had formed his own rebel group. While the bulk of the Qin forces were fighting against Xiang Yu at Julu, Liu Bang led his forces into the [[Guanzhong]] region, the heartland of the Qin dynasty, facing minimal resistance along the way. In 206&nbsp;BCE, the last Qin emperor, [[Ziying of Qin|Ziying]], surrendered the capital [[Xianyang]] to Liu Bang, bringing an end to the Qin dynasty. Liu Bang treated Ziying respectfully and forbade his troops from harming civilians and looting Xianyang, earning him the love from Qin citizens. However, when Xiang Yu eventually arrived as well, he besieged and captured the [[Hangu Pass]] garrisoned by Liu Bang's troops out of frustration that Liu Bang took the easy route and stole the glory. Liu Bang was then pressured into ceding the region to Xiang Yu despite an earlier agreement between them that whoever occupied Guanzhong first would earn the title "King of Guanzhong", and Xiang Yu also attempted to assassinate Liu Bang at the [[Feast at Swan Goose Gate]], but Liu Bang escaped thanks to his humbly courteous apologies and Xiang Yu's indecisiveness when confronted by Liu Bang's brother-in-law [[Fan Kuai]]. After Xiang Yu entered Xianyang, he allowed his troops to pillage and plunder the city and ordered the burning of the [[Epang Palace]], and had all the surrendered Qin royalties executed. Later, Xiang Yu forced Liu Bang to accept the [[fief]] of the remote, underdeveloped Bashu region (present-day [[Sichuan Basin]]), which was then used mainly as [[penal colonies]] for [[exile]]d [[criminal]]s. After [[lobbying]] by Liu Bang's friend [[Zhang Liang (Western Han)|Zhang Liang]], a Han aristocrat widely respected among the rebels for previously attempting to assassinate the First Emperor in 218&nbsp;BC, Xiang Yu reluctantly added the better developed [[Hanzhong Basin]] to Liu Bang's enfeoffment, arguing that it now fulfilled the promise of "King of Guanzhong" as Hanzhong was connected to the region via [[mountain pass]]es within the [[Qinling Mountains]]. As Liu Bang's forces relocated into the new fief, Xiang Yu had his troops following them as "escort", and Liu Bang resorted to burning the [[gallery road]]s behind his convoy as a precautionary measure to prevent being attacked in the rear and as a diplomatic gesture of accepting Xiang Yu's arrangement to never return again.

Xiang Yu then divided the former Qin Empire into numerous regional states, each ruled by either a rebel leader or a surrendered Qin general, collectively known as the [[Eighteen Kingdoms]], with the Kingdom of Chu being the [[hegemon]] holding the nominal [[suzerain]] power over the other kingdoms. Xiang Yu also honoured King Huai II with a higher title, "Emperor Yi of Chu", and declared himself "Hegemon-King of Western Chu". Shortly after that, he exiled the figurehead emperor to Chen County ({{zhi|c=郴縣}}; present-day [[Chenzhou]], [[Hunan]]), and secretly ordered his ally [[Ying Bu]], the King of Jiujiang, to intercept and assassinate Emperor Yi along the way.