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).
Han (Korean surname)
There is a controversy on where Gija is from, which is believed to be from the Chinese Shang Dynasty, Gija as a paternal uncle (or brother) of the last emperor of the Chinese Shang Dynasty, King Zhou, however it is likely that Gija is a Dongyi, a native people in the East of China. Gija's and his descendants were also believed to have the surname Han (韓) as King Jun of Gojoseon the last King of Gojoseon and descendant of Gija claimed himself as the King of Han (한왕; 韓王) with the foundation of Mahan part of the Samhan after fleeing from Wiman. With this it shows that the surname Han may have existed since the time of Gija Joseon or Gojoseon and establishes the Han (韓) clan as the oldest surname in Korea dating back to around 5000 years ago, and to have founded and ruled Gojoseon and Mahan.