Editing Chu–Han Contention (section)

=== Battle of Pengcheng ===
{{main|Battle of Pengcheng}}
In 205&nbsp;BCE, after conquering the Three Qins in the Guanzhong region, Liu Bang advanced to the east of [[Hangu Pass]] to prepare for an attack on the [[Henan]] region. [[Sima Xin]], the King of Sai, [[Dong Yi (Qin dynasty)|Dong Yi]], the King of Di, and [[Shen Yang (Eighteen Kingdoms)|Shen Yang]], the King of Henan, surrendered to Liu Bang. [[Zheng Chang]], the King of [[Han (Warring States)|Hán]], refused to submit to Liu Bang, so Liu Bang sent [[King Xin of Han|Hán Xin]] to attack and defeat him. Liu Bang then replaced Zheng Chang with Hán Xin as the new King of Hán. [[Zhang Er (Western Han)|Zhang Er]], the former King of Changshan, joined Liu Bang after losing his domain to [[Zhao Xie]] and Chen Yu.

In April–May 205&nbsp;BCE, Liu Bang attacked [[Henei Commandery|Henei]] with help from [[Wei Bao]], the King of [[Wei (state)|Western Wei]]. When Liu Bang received news that Xiang Yu had ordered the assassination of [[Emperor Yi of Chu|Emperor Yi]], he held a memorial service for the emperor and accused Xiang Yu of committing [[regicide]], using this incident as political propaganda to justify his war against Xiang Yu.

In May–June 205&nbsp;BCE, Xiang Yu defeated [[Tian Rong]] at Chengyang ({{zhi|c=城陽}}; around present-day [[Ju County]], Shandong). Tian Rong was killed while retreating to [[Pingyuan Commandery|Pingyuan]] (around present-day northwestern Shandong). Although the Kingdom of Qi had surrendered, Xiang Yu still allowed his troops to plunder and loot the Qi territories. Tian Rong's younger brother, [[Tian Heng (Eighteen Kingdoms)|Tian Heng]], made Tian Rong's son [[Tian Guang (Eighteen Kingdoms)|Tian Guang]] the new King of Qi, and continued to put up resistance against Xiang Yu.

Meanwhile, Liu Bang had mustered an army of about 560,000 with support from the kings who had surrendered to him. In September–October 205&nbsp;BCE, the Chu capital, Pengcheng ({{zhi|c=彭城}}; present-day [[Xuzhou]], Jiangsu), fell to a coalition force led by Liu Bang. When Xiang Yu received news that Liu Bang had occupied Pengcheng, he led 30,000 troops to retake Pengcheng. Liu Bang was caught off guard and his army suffered heavy casualties and his family members were captured by Chu forces. After the battle, Liu Bang lost his territorial gains in Chu and the support of his allies.