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 Wu of Han
The personal name of Emperor Wu was Liu Che (刘彻). The use of "Han" (汉) in referring to emperor Wu is a reference to the Han dynasty of which he was a part. His family name is "Liu"; the ruling family or clan of the Han dynasty shared the family name of "Liu", the family name of Liu Bang, the founding father of the Han dynasty. The character "Di" (帝) is a title: this is the Chinese word which in imperial history of China means "emperor". The character "Wu" (武) literally means "martial" or "warlike", but is also related to the concept of a particular divinity in the historical Chinese religious pantheon existing at that time. Combined, "Wu" plus "di" makes the name "Wudi", the emperor's posthumous name used for historical and for religious purposes, such as offering him posthumous honours at his tomb.