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Final years of the dynasty

In 209, Zhou Yu captured Jiangling, establishing the south's complete dominance over the Yangtze River. Meanwhile, Liu Bei and his principal adviser Zhuge Liang captured the Xiang River basin commanderies, establishing control over the southern territories of Jing province. Sun Quan was forced to cede the territory around Jiangling to Liu Bei, because he could not establish a proper authority over it after Zhou Yu's death in 210.

In 211, Cao Cao defeated a warlord coalition in the Wei valley, ending in the Battle of Huayin, capturing the territory around Chang'an. In 211, Liu Bei accepted an invitation from Liu Zhang to come to Yi Province for aiding the latter against a threat from the north, namely Zhang Lu of Hanzhong. Liu Bei met people within Liu Zhang's court who wished that he would replace Liu Zhang as the ruler of Yi Province. A year after his arrival, Liu Bei came into conflict with Liu Zhang and turned against him. In the summer of 214, Liu Bei received the surrender of Liu Zhang, capturing Yi Province, and established his regime at Chengdu. In 215, Cao Cao captured Hanzhong after attacking and receiving the surrender of Zhang Lu. He had launched the attack from Chang'an through the Qinling Mountain passes to Hanzhong. The conquest threatened Liu Bei's territory located directly to the south. Cao Cao progressively acquired additional titles and power under the puppet Emperor Xian. He became the Chancellor in 208, the Duke of Wei in 214, and the King of Wei in 217. He also compelled Sun Quan to accept suzerainty to Wei, but it had no real effect in practice.

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. In the south, Sun Quan had sent He Qin, Lu Xun, and others to expand and conquer territory in what are now southern Zhejiang and Fujian.

In 219, Liu Bei seized Hanzhong by defeating and killing General Xiahou Yuan, who served Cao Cao. Cao Cao sent reinforcements in an unsuccessful attempt to reclaim the territory. Liu Bei had now secured his territory against the north and declared himself the King of Hanzhong. In the east, Sun Quan attempted to capture Hefei from Cao Cao, but he did not succeed.

While Lu Su had been chief commander for Sun Quan in Jing Province, their policy was to maintain the alliance with Liu Bei while Cao Cao was still a threat. This changed when Sun Quan appointed Lü Meng when Lu Su died in 217. In 219, Guan Yu sailed from Jiangling up the Han River towards the city of Fan (near Xianyang), but was unable to capture it. In the autumn of 219, Lü Meng launched a surprise attack by sailing up the Yangtze towards Jiangling, resulting in its capture. Guan Yu was unable to hold his position as most of his army surrendered. He was captured and executed on Sun Quan's order. Cao Cao regained the Han valley, while Sun Quan captured all the territory east of the Yangtze Gorges.