Cao Wei

Cao Wei was one of the three states that divided China after the collapse of the Eastern Han, founded in 220 when Cao Pi compelled Emperor Xian to abdicate and proclaimed the Wei dynasty. Its territory covered the North China Plain, the Guanzhong basin and the middle Yangtze, the richest and most populous core of the old empire. Cao Pi ruled first from Xuchang and then from Luoyang, which became the dynasty's ceremonial capital. His father Cao Cao had built the regime's military power as chancellor, and his court introduced the nine-rank system that formalised recruitment by pedigree and shaped the aristocratic society of the following centuries. After the regent Sima Yi seized power in 249, the Cao emperors became puppets of the Sima clan. Wei conquered Shu Han in 263, but in 266 Sima Yan forced the last emperor to abdicate and founded the Jin dynasty, which completed the reunification of China in 280.