By 202 BC, the war between the Han Army headed by Liu Bang and the Chu forces led by Xiang Yu had continued for several years. At the Battle of Gaixia, Liu Bang besieged Xiang Yu's 100,000 soldiers with his army of 300,000, an absolute advantage over Xiang Yu. Deep into night, the Han Army sang the songs of Chu, which caused homesickness among the soldiers of Chu and accordingly weakened their morale and fighting spirit. Xiang Yu was forced to break the siege during the night with a troop of 800 cavalrymen. The troops of Han pursued and attacked with 5000 cavalrymen. Finally a duel began at the Wujiang River. Outnumbered by a large margin, Xiang Yu had no choice but to kill himself with his sword.