List of emperors of the Han dynasty
The Han dynasty was founded by the peasant rebel leader (Liu Bang), known posthumously as Emperor Gao ("r". 202 –195 BC) or Gaodi. The longest reigning emperor of the dynasty was Emperor Wu ("r". 141–87 BC), or Wudi, who reigned for 54 years. The dynasty was briefly interrupted by the Xin dynasty of the former regent Wang Mang, but he was overthrown in 23 AD and the Han dynasty was reestablished by Liu Xiu, known posthumously as Emperor Guangwu (r. 25–57 AD), or Guangwu Di. The last Han emperor, Emperor Xian ("r". 189–220 AD), was a puppet monarch of Chancellor Cao Cao (155–220 AD), who dominated the court and was made King of Wei. In 220 AD, Cao's son Pi usurped the throne as Emperor Wen of Wei ("r". 220–226 AD) and ended the Han dynasty.
Battle of Xiaoting
On 25 November 220, Emperor Xian, the figurehead monarch of the Eastern Han dynasty, abdicated in favour of Cao Pi and ended the Eastern Han dynasty. On 11 December, Cao Pi established the state of Wei to replace the Eastern Han dynasty and became its first emperor. On 10 May 221, Liu Bei declared himself emperor at Wudan (武擔; a hill in the northwest of present-day Chengdu, Sichuan) and established a new state, historically known as Shu, to contest Cao Pi's claim to the Han throne. Around the same time, Sun Quan shifted the capital of his territories from Gong'an County to E County (鄂縣; present-day Ezhou, Hubei), which he renamed "Wuchang" (武昌). On 23 September 221, Sun Quan pledged allegiance to Cao Pi and became a vassal of the Wei state; in return, Cao Pi awarded Sun Quan the title "King of Wu" (吳王).