General Han Xin And The Strategic Wei River Flood

Around the year 204 BCE, or early 203 BCE, a skilled general named Han Xin led an army against the kingdom of Qi. His mission was to subjugate Qi and deliver it into the hands of Liu Bang, the King of Han, who would found the Han Dynasty. Liu Bang’s main rival at the time was Xiang Yu, the king of Chu. Although Liu Bang and Xiang Yu only claimed to be kings, they had come to dominate the other minor kingdoms of post-Qin China, with Liu bang lording over the west and Xiang Yu commanding the east. When Xiang Yu heard that his Han rivals were moving against Qi, he sent an army of Chu soldiers, led by general Long Ju, to help King Tian Guang of Qi defend the kingdom.

The forces of Qi and the army of Long Ju combined their strength and marched together to face Han Xin’s invading troops. They intercepted the Han army before it could cross the Wei River. When the two opposing forces met, the Qi and Chu soldiers observed that the river was oddly low and shallow.

The shallow water did little to encumber the Han forces as Han Xin led half of his troops into the river. Han Xin by this point had an impressive résumé—in 204 BCE, he had personally captured the kings of Wei, Zhao and Dai in battle. Yet, the forces of Qi and Chu found the army in front of them to be underwhelming—when Long Ju led some of his troops to skirmish with the Han soldiers in the river, it seemed to the Qi and Chu forces as if Han Xin had lost his nerve. Not long after the fighting began in the shallow waters of the river, the Han army began fleeing back across the river, where the rest of their troops were still waiting.

Seeing the Han army flee before him, Long Ju apparently believed he was nearing the end of a decisive victory. Eager to deliver the killing blow, Long Ju signaled for the Chu and Qi forces to cross the river and attack the wavering Han army.

Han Xin observed from his side of the river as a significant portion of the Chu and Qi forces waded into the water. Everything had gone exactly as planned—now it was time to spring his trap. Using some sort of signal, Han Xin communicated a message upriver to a group of engineers who were eagerly awaiting orders. These men were overseeing a sandbag dam in the Wei River, which they had rigged to catastrophically fail when triggered by some sort of mechanism. When Han Xin’s message arrived, the engineers collapsed the dam and let the impatient water rush violently back into the depleted Wei River.

Before the soldiers of Qi and Chu could identify the roaring sound coming from upstream, the powerful flood was already upon them. Much of the army was drowned in the flow, but those in the frontlines who had followed Long Ju to the other side of the river were now cut off from the rest of the surviving army. Han Xin and the Han army then charged against the vulnerable troops who had survived the flood and general Long Ju was slain in the resulting massacre. King Tian Guang of Qi, who was watching the catastrophe from dry land on the other side of the river, decided that the battle was lost and fled with what remained of his army. Nevertheless, Han Xin soon intercepted and captured the fleeing king and the last remnants of his troops.

Written by C. Keith Hansley.

Picture Attribution: (Battle at the River Thi-cau, c. 18th century, [Public Domain] via Creative Commons).

Sources:

• Records of the Grand Historian (Shi ji) by Sima Qian, translated by Burton Watson. New York: Columbia University Press, 1993.