Battle of Fei River

In the late autumn of 383, beside a small river that once flowed near the Huai in present-day Anhui, a much smaller army of the Eastern Jin dynasty routed the huge invasion force of the Former Qin, the Di-led state that had united northern China. The disaster broke Former Qin apart and preserved the southern Chinese regimes, which stayed independent until the Sui dynasty reunited the country in 589.

Former Qin grew rapidly from the 350s. Its ruler, Fu Jian, conquered the Former Yan in 370, took Sichuan and Chongqing from Jin in 373 and captured Xiangyang, the gateway to the middle Yangtze, in 379. By 381 the whole north was his, and he was planning an invasion of the south.

In May 383 a Qin relief force drove off a Jin army trying to retake Xiangyang. Fu Jian then ordered a general mobilisation, reportedly calling up six of every ten able-bodied men. In August his brother Fu Rong, who had opposed the campaign, set out with an advance force said to number 300,000, and Fu Jian followed from Chang'an. The Book of Jin, the official history of the Jin dynasty, puts his total strength at 870,000. The army was a patchwork of levies from conquered lands and nomadic cavalry drawn from the Xianbei and Xiongnu, many of whom felt little loyalty to Qin.

The Jin prime minister, Xie An, directed the defence. The front on the Huai was entrusted to Xie Shi and Xie Xuan with the Beifu army, some 80,000 trained troops raised from the hereditary military followings of powerful families.

In October Fu Rong captured the Jin city of Shouyang. Hoping for a quick win, Fu Jian hurried ahead with 8,000 light cavalry and sent a captured Jin official, Zhu Xu, to call on Xie Shi to surrender. Zhu Xu instead told the Jin commanders that the Qin host had not yet assembled and urged them to strike first. A Jin detachment of 5,000 under Liu Laozhi then defeated the Qin vanguard, reportedly killing 15,000, and the Jin spread their troops in a wide line to look stronger than they were.

In November the armies faced each other across the Fei. Xie Xuan asked Fu Rong to pull back a little so that the Jin could cross and fight. Most Qin generals thought the manoeuvre too risky for such a poorly drilled army, but Fu Jian agreed, planning to attack the Jin while they were still crossing. The withdrawal turned into panic when Zhu Xu shouted that Qin had been defeated. The Jin crossed and attacked, Fu Rong was killed when his horse fell, and the whole Qin army fled, abandoning its food and equipment. By one estimate, 70 to 80 per cent of the Qin soldiers died in the fighting or from hunger and exposure during the retreat.

Fu Jian fell back to Luoyang, shielded by Murong Chui, whose army of 30,000 was one of the few still intact. Revolts broke out as news of the defeat spread. Murong Chui himself rebelled early in 384, setting off a wave of Xianbei and Qiang uprisings. Chang'an fell to the Western Yan in 385, and in the same year Fu Jian was killed by his former general Yao Chang, founder of the Later Qin. A weakened Former Qin lingered until 394. The Jin, meanwhile, advanced to the Yellow River, regaining much of the old heartland.

The battle is counted among the most important in Chinese history, because it decided that the north would not absorb the south. It is also remembered as a lesson in the value of training, morale and steady command over sheer numbers. Fu Jian had boasted that his soldiers could stop the Yangtze by throwing their whips into it; the phrase survives as a Chinese idiom.

Our 400 map shows the Jin state holding southern China in the years after the battle.