Cao Pi in the context of "Posthumous name"

The emperors of the Han dynasty were the supreme heads of government during the second imperial dynasty of China; the Han dynasty (202 BC – 220 AD) followed the Qin dynasty (221–206 BC) and preceded the Three Kingdoms (220–265 AD). The era is conventionally periodised into the Western Han (202 BC – 9 AD) and Eastern Han (25–220 AD).

The Han dynasty was founded by the peasant rebel leader Liu Bang, known posthumously as Emperor Gao (r. 202–195 BC). The longest reigning emperor of the dynasty was Emperor Wu (r. 141–87 BC), who reigned for 54 years. The dynasty was briefly interrupted by the Xin dynasty of the former regent Wang Mang, but he was killed during a rebellion on 6 October 23 AD. The Han dynasty was reestablished by Liu Xiu, known posthumously as Emperor Guangwu (r. 25–57 AD) or Guangwu Di, who claimed the throne on 5 August 25 AD. 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. On 11 December 220, Cao's son Pi usurped the throne as Emperor Wen of Wei (r. 220–226 AD) and ended the Han dynasty.

Wei (Chinese: 魏), also known as Cao Wei (曹魏) or Former Wei, was one of the major dynastic states in China during the Three Kingdoms period. The state was established in 220 by Cao Pi based upon the foundations laid by his father Cao Cao during the end of the Han dynasty. Its capital was initially located at Xuchang, and was later moved to Luoyang.

The name Wei first became associated with Cao Cao when he was named the Duke of Wei by the Eastern Han government in 213, and became the name of the state when Cao Pi proclaimed himself emperor in 220. Historians often add the prefix "Cao" to distinguish it from other Chinese states known as Wei. The authority of the ruling Cao family dramatically weakened following the deposition and execution of Cao Shuang, a regent for the dynasty's third emperor Cao Fang. Beginning in 249, another regent in Sima Yi gradually consolidated state authority for himself and his relatives, with the last Wei emperors largely being puppets of the Sima family. In 266, Sima Yi's grandson Sima Yan forced Emperor Yuan to abdicate, proclaiming himself to be emperor of the newly established Jin dynasty; he would be posthumously known as Emperor Wu (of Jin).

The end of the (Eastern) Han dynasty was the period of Chinese history from 189 to 220 CE, roughly coinciding with the tumultuous reign of the Han dynasty's last ruler, Emperor Xian. It was followed by the Three Kingdoms era (220–280 CE). During the end of the Han dynasty, the country was thrown into turmoil by the Yellow Turban Rebellion (184–205). Meanwhile, the Han Empire's institutions were destroyed by the warlord Dong Zhuo and fractured into regional regimes ruled by various warlords, some of whom were nobles and officials of the Han imperial court. The warlord Cao Cao took control of Emperor Xian and his court in 196 and began gradually reunifying the empire. Cao Cao ostensibly operated under Emperor Xian's rule, though in reality the emperor was a hostage.

Cao Cao's efforts to reunify China were rebuffed at the Battle of Red Cliffs in 208–209, when his armies were defeated by the allied forces of Sun Quan and Liu Bei. The Han dynasty formally ended in 220 when Cao Cao's son and heir, Cao Pi, pressured Emperor Xian into abdicating in his favour. Cao Pi became the emperor of a new dynasty, Cao Wei. In response, Liu Bei established the Shu Han dynasty in 221 with himself as its emperor. Sun Quan founded the Eastern Wu dynasty in 222, first adopting the title of king and later declared himself emperor in 229. The period from the end of the Han dynasty in 220 to the reunification of China proper under the Western Jin dynasty in May 280 is known as the Three Kingdoms era in Chinese history.

Cao Cao (pronunciation; [tsʰǎʊ tsʰáʊ]; Chinese: 曹操; c. 155 – 15 March 220), courtesy name Mengde, was a Chinese statesman, warlord, and poet who rose to power during the end of the Han dynasty (c. 184–220), ultimately taking effective control of the Han central government. He laid the foundation for the state of Cao Wei (220–265), established by his son and successor Cao Pi, who ended the Eastern Han dynasty and inaugurated the Three Kingdoms period (220–280). Beginning in his own lifetime, a corpus of legends developed around Cao Cao which built upon his talent, his cruelty, and his perceived eccentricities.

Cao Cao began his career as an official under the Han government and held various appointments including that of a district security chief in the capital and the chancellor of a principality. He rose to prominence in the 190s during which he recruited his own followers, formed his own army, and set up a base in Yan Province (covering parts of present-day Henan and Shandong). In 196, he received Emperor Xian, the figurehead Han sovereign who was previously held hostage by other warlords such as Dong Zhuo, Li Jue, and Guo Si. After he established the new imperial capital in Xuchang, Emperor Xian and the central government came under his direct control, but he still paid nominal allegiance to the emperor. Throughout the 190s, Cao Cao actively waged wars in central China against rival warlords such as Lü Bu, Yuan Shu, and Zhang Xiu, eliminating all of them. Following his triumph over the warlord Yuan Shao at the Battle of Guandu in 200, Cao Cao launched a series of campaigns against Yuan Shao's sons and allies over the following seven years, defeated them, and unified much of northern China under his control. In 208, shortly after Emperor Xian appointed him as Imperial Chancellor, he embarked on an expedition to gain a foothold in southern China, but was defeated by the allied forces of the warlords Sun Quan, Liu Bei, and Liu Qi at the decisive Battle of Red Cliffs.

The Huanglan or Imperial Mirror was one of the oldest Chinese encyclopedias or leishu "classified dictionary". Cao Pi, the first emperor of the Wei, ordered its compilation upon his accession to the throne in 220 and it was completed in 222. The purpose of the Huanglan was to provide the emperor and ministers of state with conveniently arranged summaries of all that was known at the time. Complete versions of the Huanglan existed until the Song dynasty (960-1279), when it became a mostly lost work, although some fragments did survive in other encyclopedias and anthologies. The Huanglan was the prototype of the classified encyclopedia and served as a model for later ones such as the (624) Tang Yiwen Leiju and the (1408) Ming Yongle dadian.

The Three Ducal Ministers (Chinese: 三公; pinyin: Sāngōng), also translated as the Three Dukes, Three Excellencies, or the Three Lords, was the collective name for the three highest officials in Ancient China and Imperial China. These posts were abolished by Cao Cao in 208 AD and replaced with the position of Grand Chancellor. When Cao Cao's son Cao Pi became King of Wei after his father's death, he reinstated the three positions. Hua Xin was made Chancellor, Jia Xu was made Grand Commandant and Wang Lang was made Grand Secretary. When Cao Pi declared himself emperor in late 220, Hua Xin was made Cao Wei's first Minister of the Masses, Jia Xu remained as Grand Commandant, and Wang Lang was made the first Minister of Works.

Lady Bian (29 January 161 – 9 July 230), also known as Empress Dowager Bian or Grand Empress Dowager Bian, formally known as Empress Wuxuan, was an empress dowager and later grand empress dowager of the state of Cao Wei during the Three Kingdoms period of China. She was the wife of Cao Cao, a warlord who rose to power in the late Eastern Han dynasty and laid the foundation of Wei. She bore Cao Cao's successor, Cao Pi, who ended the Han dynasty and founded Wei in 220 after his father's death.