Battle of Fei River
The Battle of Fei River or "Feishui" (Traditional Chinese: 淝水之戰; Hanyu Pinyin Féishŭi zhī zhàn) was a battle in 383, where Fu Jian (苻堅) of the Former Qin was defeated by the numerically inferior army of Eastern Jin. The battle is usually considered to have been decisive in that it ensured the survival of Eastern Jin and other regimes south of the Yangzi River.
Background
The state of Former Qin, lead by ethnic Di (氐) tribesman, rose rapidly from a string of successes in the 350s. Fu Jian, nephew of the founder, was a vigorous leader of tremendous drive and ambition. In 370 he conquered the state of Former Yan and in 373 seized almost all of Sichuan from the Jin. In 379, the strategically important city of Xiangyang, gateway to the Middle Yangzi fell to Qin. By 381, he had united all of north China and was preparing for an invasion of the south.
In the summer of 383 a Jin army attempted to recover Xiangyang but was driven off by a Qin relief column of 50,000 men. According to the "Chronicle of Fu Jian" in Jin shu, Fu Jian responded in the eighth month with an army of 270,000 cavalry, 600,000 infantry and 30,000 elite guards (羽林郎), marching from Chang'an. Separate columns were to push downstream from Sichuan but the main offensive would occur against the city of Shouchun on the Huai River. The Jin emperor Sima Yao (司馬曜) hurriedly made preparations for defense. He gave Huan Chong (桓沖) responsibility for the defense of the Middle Yangzi. The pressing defense of the Huai River was given to Xie An (謝安), Xie Xuan (謝玄) and the veteran 80,000-strong Beifu Army (北府兵).