The Ruxu river joins Chao Lake to the Yangzi. It is the water road north for Wu and south for Wei. In 213 Cao Cao attacked with a claimed four hundred thousand. Sun Quan met him with seventy thousand and built the Ruxu fort. After a month Cao Cao withdrew.
There is no decisive fire like Red Cliffs. The importance is the line it draws: Wei does not cross the river, and Wu does not enter the country behind Hefei. The sigh “a son should be like Zhongmou” is quoted from the Wu li in Pei’s notes. The wording can stay uncertain. The standoff is history.