In 215, Sun Quan had disputes with his ally Liu Bei over the division of southern Jing Province between their respective domains. Sun Quan sent Lü Meng and Ling Tong to seize the three commanderies of Changsha (長沙), Lingling (零陵; around present-day Yongzhou, Hunan) and Guiyang (桂陽; around present-day Chenzhou, Hunan) from Liu Bei, and then ordered Lu Su to station at Yiyang as a precaution against any retaliation by Liu Bei's general Guan Yu, who was in charge of his lord's territories in southern Jing Province. Gan Ning joined Lu Su at Yiyang.