After Liu Bei had captured Yi Province from Liu Zhang in 214, Sun Quan—who had been engaged with Cao Cao in the southeast at the region between the Huai and Yangtze rivers during the intervening years—turned his attention to the middle Yangtze. Cao Cao and Sun Quan had gained no success in breaking each other's positions. Liu Fu, an administrator under Cao Cao, had established agricultural garrisons at Hefei and Shouchun to defend Cao's territory near the Huai river. Sun Quan resented the fact that Liu Bei, a weaker ally, had gained so much territory west of him and demanded a larger share of the Xiang River basin. In 215, Lü Meng (Sun Quan's officer) was sent to capture Jing province's southern commanderies, but Guan Yu (Liu Bei's general) launched a counterattack. Later that year, Liu Bei and Sun Quan reached a settlement that the Xiang River would serve as the border between their territories.