Shu Han (蜀汉) was the western kingdom of the Three Kingdoms period. Liu Bei declared himself emperor in 221, claiming legitimacy as a descendant of the Han imperial house and intent on restoring the Han. The state lasted until 263, when Wei (by then under the Sima family) conquered it.
Foundation
Liu Bei built his power through the late Han and warlord period with the help of Zhuge Liang, Guan Yu, Zhang Fei, and others. After taking Yi Province from Liu Zhang and surviving the Battle of Yiling against Eastern Wu, he ruled from Chengdu. His successor, Liu Shan, relied heavily on Zhuge Liang for administration and for the northern expeditions against Cao Wei.
Role in the tripartite division
Shu was the smallest of the three kingdoms in land and population. Its strength lay in defensible terrain, Zhuge Liang’s governance and strategy, and later Jiang Wei’s campaigns. The Northern Expeditions never achieved a lasting breakthrough; after Zhuge Liang’s death in 234, Shu’s offensive capacity waned.
Fall
In 263, Wei (effectively under the Sima clan) sent Deng Ai and Zhong Hui to invade. Jiang Wei held the passes, but Deng Ai crossed the mountains and reached Chengdu. Liu Shan surrendered, and Shu Han ceased to exist. It was the first of the three kingdoms to fall.