In August of 198 CE, the third year of the Jian'an Era, Liu Biao and Liu Bei joined forces to send troops against Jiangdong under an imperial edict.
That month, upon learning the news, Sun Ce followed Zhou Yu's plan and marched into Danyang, intending to use the Yangtze River's natural barrier to block Liu Bei's forces.
Zhou Yu, then the Commander of Jiangdong's naval forces, boldly pushed west, charged into Jing Province, and utterly defeated its navy.
Though this gave Jiangdong's navy an early advantage, it also exposed the weaknesses of Jing Province's fleet to Liu Biao. He replaced the commander on the eve of battle, appointing Huang She as commander-in-chief and placing Cai Mao in charge of Jing Province's navy.
This move directly reversed Jing Province's naval decline and successfully pushed the battle line to Jing Province's border.
The two armies faced each other at Pengli Lake for more than ten days. By mid-September, seeking to break the deadlock, the Jiangdong army deliberately opened up the Spring Valley defense line, luring Lu Su, Liu Bei's naval commander, into attacking.
Yet through Zhuge Liang and Lu Su's combined stratagems, Zhou Yu took the bait and sent out his troops, allowing Jing Province's navy to launch a surprise attack on his rear.
In this battle, the combined forces of Liu Bei and Liu Biao numbered more than twenty thousand, while Zhou Yu had only a little over eight thousand men. In the end, at the cost of more than five thousand casualties between the two allied sides, they nearly wiped out Jiangdong's navy.
Jing Province's army lost more than four thousand men, while Liu Bei's army lost more than a thousand. Jiangdong lost over seven thousand men, and only several hundred remnants under Zhou Yu escaped.
Among the allied generals,