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).
Liu Yao
Liu Yao (died 329), courtesy name Yongming, was the final emperor of the Xiongnu state Han Zhao. He became emperor in 318 after most other members of the imperial Liu clan were massacred by Jin Zhun in a coup. However, the empire was soon divided in half, as the general Shi Le declared independence and established Later Zhao. In a decisive battle in early 329, Shi captured and executed him, and while his sons Liu Xi the Crown Prince and Liu Yin the Prince of Nanyang continued to hold out for nearly a year, the Han Zhao state fell later that year.