From 206–202 BC, Liu Bang engaged Xiang Yu in a power struggle – historically known as the Chu–Han Contention – for supremacy over China, while simultaneously attacking and subjugating the other kingdoms. In 203 BC, Xiang Yu and Liu Bang came to an armistice, known as the Treaty of Hong Canal, which divided China into east and west along the Hong Canal under the Chu and Han regimes respectively. A few months later, Liu Bang renounced the treaty and attacked Xiang Yu again. In 202 BC, Xiang Yu lost to Liu Bang at the Battle of Gaixia and committed suicide, after which Chu surrendered to Han. Liu Bang had unified much of China under his control by then.
The Han forces had earned many major victories against Chu, but they still did not control most of the country. Most of eastern China was still under Chu control. Eventually Xiang Yu was able to reorganize his forces, and strike back at Liu Bang.
At this point, major disagreements had occurred between Liu Bang and Han Xin. The primary reasons were because Liu Bang refused to give Han Xin too much control over the Han army, and his refusal to use many of Han Xin’s suggestions. As a result, Han Xin withheld his forces in Qi as Liu Bang was under siege from Xiang Yu. Liu Bang was only able to hang on because of the assistance from another excellent military strategist, Zhang Liang.
Xiang Yu was one of the best warrior-commanders in Chinese history, but in most battles he rarely paid sufficient attention to resource logistics. In this battle, Zhang Liang was successful in assaulting Xiang Yu’s supply lines, which Xiang Yu did not care much about, and this greatly hurt the Chu army’s effectiveness. On the other hand, Zhang Liang was successful in keeping the Han supply lines open. During a conversation, Xiang Yu’s archer hit Liu Bang with an arrow, which wounded his lung. However, Liu Bang was able to hide this fact from his own army and Xiang Yu, hence keeping the morale of the Han troops high.
Sensing the tension between Liu Bang and Han Xin, Xiang Yu tried to persuade Han Xin to ally with him, or at least to stay neutral in this war. Xiang Yu warned Han Xin that he would be in grave danger if Liu Bang comes out victorious. Xiang Yu even offered to openly accept Han Xin’s Qi as a third nation after Chu and Han. However, due to the past history between the two Han Xin refused any diplomatic relationship with Xiang Yu.
Xiang Yu then threatened to kill Liu Bang’s captured father and wife and have them cooked over a fire, to force Liu Bang to surrender. Liu Bang simply replied that since the two had been named ‘brothers’ (during the earlier years of the revolt against Qin Dynasty) he would be effectively cooking his own father, and that Xiang Yu should not forget to send him a cup of ‘their’ father’s flesh to share as good brothers, but Xiang Yu still did not kill them. At one point, Xiang Yu was about to capture Liu Bang. Finally, Liu Bang agreed with everything that Han Xin requested, and Han Xin finally agreed to help. Later, with the arrival of Han Xin, Liu Bang was able to convince Xiang Yu to agree to a peace treaty. At the end, both parties agreed that the two countries of Han and Chu could co-exist peacefully. Liu Bang’s father and wife were returned to Liu Bang. Then, in October 202 BC, Xiang Yu started to move his forces back east.
Unknown to Xiang Yu, this was a tactic from Han Xin. The Chu forces had sieged the Han fortress for a long time, leaving them tired. On top of that, Chu troops were getting less food than they needed to fight effectively. When news reached them that the war was over, and that there would be long term peace ahead, they were overjoyed.
Han Xin then led many attacks against the joyful Chu forces. In anger, Xiang Yu tried to fight his way back to Liu Bang’s fortress, but Han Xin had set up many traps and ambushes along the way. Finally Xiang Yu decided that a quick victory was no longer possible with his low morale troops, and decided to temporarily retreat back to the Chu capital, and regroup there.
Han Xin knew that he could not let Xiang Yu return to the capital. Han Xin ordered his forces to increase the number of ambushes, in order to force the Chu troops into a canyon area near Gaixia, where Xiang Yu could not move at will. As the ambushes increased, Xiang Yu, an excellent strategist, became more and more certain that the main traps would await him inside the canyon. So although his troops were constantly ambushed, he insisted that his troops head straight back to the capital city through the main road as fast as they could, avoiding the side paths through the canyon.
Unfortunately for Xiang Yu, fortune turned against him, despite his military genius. In one of the ambushes, Xiang Yu’s beloved wife, Consort Yu (虞姬), who always traveled with his forces, was captured by Han troops. Han Xin immediately ordered that she be taken into the canyon. Xiang Yu, without a choice, sent most of his tired forces back to the capital on the main road, while he himself led a smaller force of 100,000 soldiers into the canyon to save his wife.
Xiang Yu hoped to save his wife quickly and to get out before becoming totally entrapped. However, the Han forces, under Han Xin’s orders, moved his wife deep into the canyon. By the time he finally reached them and saved his wife, he and his army were already too deep into the canyon to retreat safely.
Han Xin then proceeded with his master plan: “Ambush from Ten Sides” (十面埋伏). Han Xin first fought Xiang Yu face to face, and then retreated. Xiang Yu immediately gave chase, but soon found himself trapped among the numerous Han army. Everywhere Xiang Yu led his forces, ambushes and traps awaited them. With the repeated ambushes and encirclements, the Han troops began to elongate Xiang Yu’s columns and disrupt their formation, allowing their decimation piecemeal. This not only caused heavy casualties for Chu, but also crushed the Chu army’s morale, since escaping alive seemed impossible. The troops were trapped without supply in the canyon until December 202 BC.
To further break the Chu army’s spirit, Han Xin employed the “Chu Song from Four Sides” (四面楚歌) tactic. He ordered the Han soldiers and captured Chu troops to sing Chu songs. The Chu songs made the Chu troops remember their families back home, greatly reducing their will to fight. Even Xiang Yu himself thought that the Western Chu had been conquered, while he had been trapped there, and his cause was lost.
Then the Chu soldiers started to leave their camps and escape on their own. Initially Xiang Yu tried, with force, to stop his troops from leaving the ranks. But when the soldiers and his wife begged of him to let the soldiers go home, Xiang Yu sadly agreed. On the same night, Xiang Yu’s wife, at age 16, committed suicide, because she considered herself the primary cause of the fall of the Western Chu. This event broke even Xiang Yu’s spirit.
About 800 loyal soldiers left behind and stayed with Xiang Yu, swearing to fight for him until the very end. Xiang Yu was impressed with their loyalty, and promised to lead them to safety. Most of the soldiers are believed the survivors of the original 8000 followers of Xiang Yu to fight against Qin Dynasty. At the end of Xiang Yu’s life, he said he felt very guilty because he could not bring any of them back to their hometown.
Xiang Yu’s suicide
Han Xin successfully broke the spirits of the Chu troops, and that broke the Chu ranks, without a fight, as he expected. But the event had an advantage to Xiang Yu. When the Chu army size was still large, they could not move as they wanted, since they were easy to spot. But now Xiang Yu only had 800 men on horses, which allowed him to move much more easily. Xiang Yu was able to break though the traps and ambushes, and escaped the canyon with about a hundred men.
Eventually, Han Xin discovered in shock that Xiang Yu had escaped from the entrapped canyon. Upon discovering this, Liu Bang ordered 5,000 elite cavalry to chase down Xiang Yu. Liu Bang ordered the cavalry to not kill Xiang Yu, but to capture him.
Unfortunately for Xiang Yu, after he left the canyon, he soon got lost. He tried to ask local people for directions back to Chu, but they pointed him in the wrong direction, with this being possibly intentional given their loyalty towards Han. Xiang Yu then went into the swamps, costing him valuable time for escape. (The fact is disputed, as it is absent from certain Chinese historiographies, and most historians believe it to be fictional.) At the end, the elite cavalry chased him to Wu River (烏江). Then Xiang Yu refused to surrender. Xiang Yu had an opportunity to use a local boatman to escape across the river back into Chu territory, but he had too much pride to do so. Instead, he tried to persuade the last 26 of his loyal soldiers to escape but they all refused and wished to make a last stand against the soldiers that attempted to capture their lord alive, killed hundreds of them in this process. After being seriously wounded, Xiang Yu slit his own throat.
The loss of Xiang Yu was a major blow to Western Chu. Xiang Yu’s brother tried to take command over Chu, but he was mostly a fighter and not a military strategist. No one else in Chu had the army-leading ability of Xiang Yu, and hence no one could win any battles against Han Xin and Zhang Liang. Soon, Chu fortresses started to surrender to Liu Bang, and Liu Bang treated all surrendering Chu forces with respect. Had Xiang Yu successfully retreated into Chu, Chu might have been able to stop Han’s advance, at least for a while.
Soon after the death of Xiang Yu, Chu would fall to Han. Thus the Han Dynasty, one of the greatest Chinese dynasties, was established.