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).
Emperor Cheng of Han
Emperor Cheng of Han (51 BC – 17 April 7 BC) was an emperor of the Chinese Han Dynasty ruling from 33 until 7 BC. He succeeded his father Emperor Yuan of Han. Under Emperor Cheng, the Han dynasty continued its slide into disintegration while the emperor's maternal relatives of the Wang clan continued their slow grip on power and on governmental affairs as promoted by the previous emperor. Corruptions and greedy officials continued to plague the government and as a result rebellions broke out throughout the country. Emperor Cheng died childless after a reign of 26 years (both of his sons by concubines died in infancy, one of them starved to death) and was succeeded by his nephew Emperor Ai of Han.