The Conquest of Yi Province (益州之战) was Liu Bei’s campaign in 214 CE to take control of Yi Province (modern Sichuan) from Liu Zhang. The campaign established Liu Bei’s territorial base in the west and provided the foundation for Shu Han.
Background
Liu Zhang, the governor of Yi Province, was seen as weak and indecisive. Zhang Song and others invited Liu Bei to take control, believing he would be a stronger leader. Liu Bei initially entered Yi Province as an ally to help against Zhang Lu, but tensions grew.
The campaign
In 214, Liu Bei turned against Liu Zhang and launched a campaign to take Yi Province. Pang Tong served as strategist but was killed early in the campaign at Luo County. Zhuge Liang was called from Jing Province to join the campaign, bringing Zhang Fei and Zhao Yun.
Siege of Chengdu
Liu Bei’s forces advanced toward Chengdu, the capital of Yi Province. After several battles and the fall of key cities, Liu Zhang surrendered Chengdu to Liu Bei in 214. Liu Bei took control of Yi Province, establishing his territorial base.
Aftermath
The conquest gave Liu Bei control of the fertile Sichuan Basin and strategic mountain passes. Yi Province became the core territory of what would become Shu Han. Liu Bei declared himself King of Hanzhong in 219 and Emperor of Shu Han in 221, with Chengdu as his capital.
Historical significance
The Conquest of Yi Province established Liu Bei as a major territorial power. Combined with his holdings in Jing Province, it gave him the resources to declare himself emperor and establish Shu Han as one of the Three Kingdoms.