Lü Meng
By November 219, Sun Quan had already secretly agreed to ally with Cao Cao against Liu Bei. He ordered Lü Meng and others to lead troops to invade Liu Bei's territories in Jing Province while he followed behind with reinforcements. At Xunyang (尋陽; present-day Huangmei County, Hubei), Lü Meng ordered his men to hide in vessels disguised as civilian and merchant ships and sail towards Jiangling, the capital of Nan Commandery. Along the way, Lü Meng employed infiltration tactics to disable the surveillance towers set up along the river so that Guan Yu would be unaware of the invasion. This event is called "crossing the river in civilian clothing" (白衣渡江) in the 14th-century historical novel "Romance of the Three Kingdoms".