Eastern Wu in the context of "Wu (region)"

The Three Kingdoms of Cao Wei, Shu Han, and Eastern Wu dominated China from AD 220 to 280 following the end of the Han dynasty. This period was preceded by the Eastern Han dynasty and followed by the Western Jin dynasty. Academically, the periodisation begins with the establishment of Cao Wei in 220 and ends with the conquest of Wu by Jin in 280. The period immediately preceding the Three Kingdoms, from 184 to 220, was marked by chaotic infighting among warlords across China as Han authority collapsed. The period from 220 to 263 was marked by a comparatively stable arrangement between Cao Wei, Shu Han, and Eastern Wu. This stability broke down with the conquest of Shu by Wei in 263, followed by the usurpation of Cao Wei by Jin in 266 and ultimately the conquest of Wu by Jin in 280.

The Three Kingdoms period including the collapse of the Han was one of the most dangerous in Chinese history due to multiple plagues, widespread famines, and civil war. A nationwide census taken in 280, following the reunification of the Three Kingdoms under the Jin showed a total of 2,459,840 households and 16,163,863 individuals which was only a fraction of the 10,677,960 households, and 56,486,856 individuals reported during the Han era. While the census may not have been particularly accurate due to a multitude of factors of the times, in 280, the Jin did make an attempt to account for all individuals where they could.

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.

The Jin dynasty or the Jin Empire, officially Jin, sometimes distinguished as the Sima Jin or the Two Jins, was an imperial dynasty in China that existed from 266 to 420. It was founded by Sima Yan, eldest son of Sima Zhao, who had previously been declared the King of Jin. There are two main divisions in the history of the dynasty. The Western Jin (266–316) was established as the successor to Cao Wei after Sima Yan usurped the throne from Cao Huan. The capital of the Western Jin was initially in Luoyang, though it later moved to Chang'an (modern Xi'an). In 280, after conquering Eastern Wu, the Western Jin ended the Three Kingdoms period and reunited China proper for the first time since the end of the Han dynasty.

From 291 to 306, a series of civil wars known as the War of the Eight Princes were fought over control of the Jin state which weakened it considerably. In 304, the dynasty experienced a wave of rebellions by non-Han ethnicities termed by exonym as "Five Barbarians". The "barbarians" went on to establish nonpermanent dynastic states in northern China. This helped to usher in the Sixteen Kingdoms era of Chinese history, in which states in the north rose and fell in rapid succession, constantly fighting both one another and the Jin. Han-Zhao, one of the northern states established during the disorder, sacked Luoyang in 311, captured Chang'an in 316, and executed Emperor Min of Jin in 318, ending the Western Jin era. Sima Rui, who succeeded Emperor Min, then reestablished the Jin dynasty with its capital in Jiankang (modern Nanjing), inaugurating the Eastern Jin (317–420).

The conquest of Wu by Jin was a military campaign launched by the Jin dynasty against the state of Wu from late 279 to mid 280 at the end of the Three Kingdoms period of China. The campaign, which started in December 279 or January 280, concluded with complete victory for the Jin dynasty on 1 May 280 when the Wu emperor Sun Hao surrendered. After the campaign, the Jin emperor Sima Yan (Emperor Wu) changed the era name of his reign from "Xianning" to "Taikang". Hence, the campaign has also been referred to as the Taikang campaign.

The campaign is significant in pre-1911 Chinese military history as it not only ended the chaos of the Three Kingdoms period and reunified China under the Jin dynasty, but was also the first successful large-scale military operation in Chinese history that involved a massive invasion force crossing the Yangtze. Among other aspects, its multi-directional approach, invasions by both land and water, and the sending of a naval fleet downstream along the Yangtze, have had strong influences on subsequent battles in Chinese military history.

Cao Pi (pronunciation) (c.late 187 – 29 June 226), courtesy name Zihuan, was the first emperor of the state of Cao Wei in the Three Kingdoms period of China. He was the second son of Cao Cao, a warlord who lived in the late Eastern Han dynasty, but the eldest son among all the children born to Cao Cao by his concubine (later wife), Lady Bian. According to some historical records, he was often in the presence of court officials in order to gain their support. He was mostly in charge of defence at the start of his career. After the defeat of Cao Cao's rival Yuan Shao at the Battle of Guandu, he took Yuan Xi's wife, Lady Zhen, as a concubine, but in 221 Lady Zhen died and Guo Nüwang became empress.

On 25 November 220, Cao Pi forced Emperor Xian, the last ruler of the Eastern Han dynasty, to abdicate in his favour, after which on 11 December 220 he proclaimed himself emperor and established the state of Cao Wei. Cao Pi continued the wars against the states of Shu Han and Eastern Wu, founded by his father's rivals Liu Bei and Sun Quan, respectively, but did not make significant territorial gain in the battles. Unlike his father, Cao Pi concentrated most of his efforts on internal administration rather than on waging wars against his rivals. During his reign, he formally established Chen Qun's nine-rank system as the base for civil service nomination, which drew many talents into his government. On the other hand, he drastically reduced the power of princes, stripping off their power to oppose him, but at the same time, rendering them unable to assist the emperor if a crisis arose within the state. After Cao Pi's death, his successor Cao Rui granted him the posthumous name "Emperor Wen" and the temple name "Gaozu".

Romance of the Three Kingdoms (traditional Chinese: 三國演義; simplified Chinese: 三国演义; pinyin: Sānguó Yǎnyì) is a 14th-century historical novel attributed to Luo Guanzhong. It is set in the turbulent years towards the end of the Han dynasty and the Three Kingdoms period in Chinese history, starting in 184 CE and ending with the reunification of the land in 280 by the Western Jin. The novel is based primarily on the Records of the Three Kingdoms, written by Chen Shou in the 3rd century.

The story–part historical and part fictional–romanticises and dramatises the lives of lords and their retainers, who tried to supplant the dwindling Han dynasty or restore it. While the novel follows hundreds of characters, the focus is mainly on the three power blocs that emerged from the remnants of the Han dynasty, and would eventually form the three states of Cao Wei, Shu Han, and Eastern Wu. The novel deals with the plots, personal and military battles, intrigues, and struggles of these states to achieve dominance for almost 100 years.

Chen Zhuo (fl. 3rd century) was a Chinese astronomer who lived in the Three Kingdoms period (220–280) of China. He served as an imperial astronomer in the state of Eastern Wu (222–280). He collected the works of earlier astronomers of the Han dynasty and combined them into a single system. His star catalogue listed 1,464 stars in 283 constellations. His works were lost over the course of history, but information on his system of constellations survives in Tang dynasty records, notably by Qutan Xida.