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).
Cheng Yu
Cheng Yu (141 – December 220), originally named Cheng Li, courtesy name Zhongde, was an official who lived during the late Eastern Han dynasty of China. He was an adviser to Cao Cao, the warlord who became the "de facto" head of the Han central government during that period. He died in December 220 – a few months after Cao Cao's son, Cao Pi, usurped the throne from Emperor Xian (the last Han emperor) and established the state of Cao Wei, an event marking the start of the Three Kingdoms period in China. Cheng Yu was described as a tall man (approximately 1.91 metres) with a beautiful long beard. He was from Dong'e County in present-day Shandong. He was best known in his time for his abnormal approach to cope with a shortage of grain: instead of sending hostages to Cao Cao's rival, Yuan Shao, in exchange for food supplies, he advised Cao Cao to feed his army with human flesh. He was also noted for his expertise in military tactics, which helped Cao Cao defeat Yuan Shao at the Battle of Guandu in 200 and consolidate control over northern China. It is widely agreed that his numerous contributions laid the foundation of the Cao Wei state; the reason he was not promoted to the rank of a duke was only because of his aforementioned strategy to cope with the food shortage in Yan Province. After Cheng Yu's death, Cao Pi honoured him with the posthumous title "Marquis Su", meaning "solemn marquis".