In 217, when Lu Su died, Lü Meng took over command of the former's troops, numbering over 10,000, and moved west to the garrison at Lukou (陸口; at Lushui Lake near present-day Chibi, Hubei). Lü Meng was also appointed as the Administrator () of Hanchang Commandery (漢昌郡; southeast of present-day Pingjiang County, Hunan) and received Xiajun (), Liuyang (), Hanchang and Zhouling () counties as his personal marquisate. He was stationed near the Sun-Liu border, which was guarded by Liu Bei's general Guan Yu on the other side. Lü Meng was aware of Guan Yu's military prowess and his intention of seizing Sun Quan's territories in Jing Province. He also knew that Guan Yu was in a strategic position on the upstream of the Yangtze River. He recognised that the temporary stability and truce between Sun Quan and Liu Bei would not last long.