[Why] In the north, the Former Qin emperor Fu Jian had basically pacified all rivals and yearned to unify the realm. He personally led an army self-described as a million-strong steppe-and-infantry tide and stormed south to swallow the partial Eastern Jin in Jiangnan. [What] The Eastern Jin court dispatched Xie Shi and Xie Xuan with eighty thousand Beifu elites to meet the foe. The Jin army seized the moment of Fu Jian's tactical adjustment at the Fei River to launch a surging charge, and the Qin army collapsed in panic, with Fu Jian retreating in defeat amid the rumor of winds and cranes. [Who] Xie An was the composed and unshaken worthy minister of Eastern Jin, calmly seated at command quarters in Jiankang. Xie Xuan was the brave and brilliant vanguard general, while Fu Jian brought political ruin upon himself through pride and contempt for the enemy. [How] This celebrated victory of few against many preserved the lineage of Jiangnan Han civilization from total interruption. It directly collapsed the Former Qin empire in an instant and solidified the geopolitical fragmentation of Northern and Southern Dynasties.
Why
The historic event of Battle of Fei River represents a key developmental peak of the Huaxia dynastic system. Securing the survival of Southern culture and southern lineage. By establishing this moral or administrative benchmark, it continues to shape the structural and philosophical fabric of ancient Chinese statecraft.