Emperor Xian of Han
Cao Cao died on 15 March 220. His son and successor, Cao Pi, soon forced Emperor Xian to abdicate the throne in favour of himself, ending the Han dynasty. Cao Pi established a new state known as Cao Wei (sometimes known inaccurately as the Kingdom of Wei), and he granted Emperor Xian a noble title – Duke of Shanyang (山陽公). The former Emperor Xian died in 234 and was buried with honours befitting an emperor, using Han ceremonies, and the then emperor of Wei, Cao Rui, was one of the mourners. As Emperor Xian's crown prince was already dead, his grandson Liu Kang (劉康) inherited his dukedom, which lasted for 75 more years and two more dukes, Liu Jin (劉瑾) and Liu Qiu (劉秋), until the line was exterminated by invading Xiongnu tribes in about 309, during the Jin dynasty. This practice of an emperor conferring hereditary nobility on his predecessor, from whom he usurped the throne, was known as "er wang san ke" (二王三恪).
History of the Han dynasty
Eventually, due to his good reputation, Huo Qubing's half-brother Huo Guang was entrusted by Wu to form a triumvirate regency alongside ethnically Xiongnu Jin Midi (d. 86 BCE) and Shangguan Jie (上官桀) (d. 80 BCE) over the court of his successor, the child Liu Fuling, known posthumously as Emperor Zhao of Han (r. 87–74 BCE). Jin Midi died a year later and by 80 BCE Shangguan Jie and Imperial Counselor Sang Hongyang were executed when they were accused of supporting Emperor Zhao's older brother Liu Dan (劉旦) the King of Yan as emperor; this gave Huo unrivaled power. However, he did not abuse his power in the eyes of the Confucian establishment and gained popularity for reducing Emperor Wu's taxes.