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).
Yang You
Emperor Gong of Sui (隋恭帝) (605 – 14 September 619), personal name Yang You (楊侑), was an emperor of the Chinese Sui Dynasty. Traditionally, he was considered the last emperor of the dynasty because he was the one who formally yielded the throne to the founding emperor to the succeeding Tang Dynasty, Emperor Gaozu of Tang (Li Yuan), although after him, his brother Yang Tong claimed the throne and continued to do so until 619. Li had rebelled against the rule of Yang You's grandfather Emperor Yang of Sui in 617 and captured the capital Chang'an later that year, seizing Yang You and declaring him emperor, although only the commanderies under Li's control recognized him as emperor; the rest of the commanderies continued to recognize Emperor Yang as emperor. In 618, after news arrived that Emperor Yang had been killed by the general Yuwen Huaji, Li had the young emperor yield the throne to him. The former emperor died the following year, probably on the new emperor's orders.