Yi Province (益州) was a vast administrative region covering the Sichuan Basin and surrounding mountainous areas. Protected by natural barriers and blessed with fertile land, it became the foundation of Liu Bei’s Shu Han kingdom.
Historical significance
Yi Province was established during the Han dynasty, encompassing modern Sichuan Province and Chongqing Municipality. The Sichuan Basin was one of China’s most agriculturally productive regions, supported by the Min and Tuo rivers. The surrounding mountains provided natural defences, making the province difficult to invade. This isolation allowed Yi Province to remain relatively stable while central China was ravaged by war.
Under Liu Yan and Liu Zhang
Liu Yan was appointed Governor of Yi Province in 188 during the turmoil of the late Han period. He ruled until his death in 194, when his son Liu Zhang inherited the position. Liu Zhang was known for his kindness but lacked the decisiveness and military skill needed to maintain power in the chaotic Three Kingdoms era.
Liu Zhang’s officials Zhang Song and Fa Zheng believed Liu Zhang was too weak to defend against external threats, particularly from Zhang Lu in Hanzhong to the north. They secretly invited Liu Bei to enter Yi Province and take control, believing Liu Bei — a fellow member of the Han imperial clan — would be a better ruler.
Liu Bei’s conquest
In 211, Liu Bei entered Yi Province ostensibly to help Liu Zhang defend against Zhang Lu. Liu Bei was welcomed and given supplies and troops. However, tensions grew between the two Liu clans. Fa Zheng and Zhang Song urged Liu Bei to seize the province for himself.
By 213, Liu Bei had turned against Liu Zhang. The war lasted two years. Liu Bei’s forces, commanded by Zhuge Liang, Zhang Fei, and Zhao Yun, advanced from multiple directions. In 214, Liu Bei laid siege to Chengdu, the provincial capital. Liu Zhang surrendered, and Liu Bei took control of Yi Province.
Base of Shu Han
Yi Province became the territorial core of Shu Han when Liu Bei declared himself king in 219 and emperor in 221. Zhuge Liang developed the province’s economy, improved agriculture, and organised the military. The province’s isolation protected Shu Han from direct invasion for decades.
The Sichuan Basin’s agricultural wealth supported Shu Han’s armies. The province was known for its silk production, salt wells, and iron mines. Chengdu, the capital, became a centre of administration and culture.
Hanzhong and northern defences
In 219, Liu Bei captured Hanzhong Commandery from Cao Cao, securing the northern approaches to Yi Province. This victory allowed Liu Bei to claim the title of King of Hanzhong and provided a base for future northern expeditions. Hanzhong was the gateway through which Liu Bei’s forces could exit the Sichuan Basin and threaten the Guanzhong region.
Southern campaigns
After Liu Bei’s death in 223, rebellions broke out in the southern commanderies of Yi Province — the Nanzhong region. Zhuge Liang personally led a campaign in 225 to pacify the south, capturing and releasing Meng Huo seven times to win the loyalty of the southern tribes. The campaign secured Shu’s southern flank and extracted resources for the northern expeditions.
Northern expeditions
From 228 to 234, Zhuge Liang launched five Northern Expeditions from Yi Province against Cao Wei. The campaigns were launched from Hanzhong, using the mountain passes to enter the Guanzhong plain. Though Zhuge Liang achieved tactical victories, the campaigns ultimately failed to capture Chang’an or restore the Han dynasty. Zhuge Liang died at the Wuzhang Plains in 234.
Fall of Shu
In 263, Deng Ai led Wei forces through the mountainous terrain of Yinping, bypassing Shu’s main defences. The Wei army reached the Chengdu plain. Liu Shan, Liu Bei’s son and the last emperor of Shu Han, surrendered without a fight. Yi Province was incorporated into Wei territory.
Two years later, in 266, the Sima family established the Jin dynasty, replacing Wei. In 280, Jin conquered Eastern Wu, ending the Three Kingdoms period and reunifying China.
Modern region
Today, the region of ancient Yi Province comprises Sichuan Province and Chongqing Municipality. Chengdu and Chongqing remain major cities. The region is known for its distinctive culture, cuisine, and historical sites from the Three Kingdoms period. The Sichuan Basin’s agricultural productivity continues to support a large population.
See also
- Liu Bei — founder of Shu Han, based in Yi Province
- Zhuge Liang — administrator and strategist of Shu Han
- Liu Zhang — previous governor who surrendered to Liu Bei
- Chengdu — capital of Yi Province and Shu Han
- Hanzhong — northern gateway to Yi Province
- Northern Expeditions — Zhuge Liang’s campaigns from Yi Province
- Fall of Shu — the conquest that ended Shu Han
References
- Chen Shou, Records of the Three Kingdoms (三国志), Shu 1–5
- Fan Ye, Book of the Later Han (后汉书)
- Sima Guang, Zizhi Tongjian (资治通鉴)
- de Crespigny, Rafe. A Biographical Dictionary of Later Han to the Three Kingdoms