Wu Sangui in the context of "Revolt of the Three Feudatories"

The Qing dynasty (/tʃɪŋ/ CHING), officially the Great Qing, was a Manchu-led imperial dynasty of China and an early modern empire in East Asia. The last imperial dynasty in Chinese history, the Qing dynasty was preceded by the Ming dynasty and succeeded by the Republic of China. At its height of power, the empire stretched from the Sea of Japan in the east to the Pamir Mountains in the west, and from the Mongolian Plateau in the north to the South China Sea in the south. Originally emerging from the Later Jin dynasty founded in 1616 and proclaimed in Shenyang in 1636, the dynasty seized control of the Ming capital Beijing and North China in 1644, traditionally considered the start of the dynasty's rule. The dynasty lasted until the Xinhai Revolution of October 1911 led to the abdication of the last emperor in February 1912. The multi-ethnic Qing dynasty assembled the territorial base for modern China. The Qing controlled the most territory of any dynasty in Chinese history, and in 1790 represented the fourth-largest empire in world history to that point. With over 426 million citizens in 1907, it was the most populous country at the time.

Nurhaci, leader of the Jianzhou Jurchens and House of Aisin-Gioro who was also a vassal of the Ming dynasty, unified Jurchen clans (known later as Manchus) and founded the Later Jin dynasty in 1616, renouncing the Ming overlordship. As the founding Khan of the Manchu state he established the Eight Banners military system, and his son Hong Taiji was declared Emperor of the Great Qing in 1636. As Ming control disintegrated, peasant rebels captured Beijing as the short-lived Shun dynasty, but the Ming general Wu Sangui opened the Shanhai Pass to the Qing army, which defeated the rebels, seized the capital, and took over the government in 1644 under the Shunzhi Emperor and his prince regent. While the Qing became a Chinese empire, resistance from Ming rump regimes and the Revolt of the Three Feudatories delayed the complete conquest until 1683, which marked the beginning of the High Qing era. As an emperor of Manchu ethnic origin, the Kangxi Emperor (1661–1722) consolidated control, relished the role of a Confucian ruler, patronised Buddhism, encouraged scholarship, population and economic growth.

The Shun dynasty, officially the Great Shun, also known as Li Shun, was a short-lived dynasty of China that existed during the Ming–Qing transition. The dynasty was founded in Xi'an on 8 February 1644, the first day of the lunar year, by Li Zicheng, the leader of a large peasant rebellion, by proclaiming himself "emperor" (皇帝) instead of the title "king" (王) before founding the dynasty.

The capture of Beijing by the Shun forces in April 1644 marked the end of the Ming dynasty, but Li Zicheng failed to solidify his political and military control, and in late May 1644 he was defeated at the Battle of Shanhai Pass by the joint forces of Ming general Wu Sangui (who had defected to the Qing dynasty), with Manchu prince Dorgon. When he fled back to Beijing in early June, Li finally proclaimed himself the Yongchang Emperor of the Great Shun and left the capital the next day after setting the palace ablaze and ransacking the government offices. He may have intended to resume his Imperial claims later on by proclaiming his accession in the Forbidden City. After the death of the emperor, Shun remnants joined with the Southern Ming in Nanjing, while continuing to refer to Li as their "deceased emperor". The Shun dynasty weakened dramatically after the death of Li Zicheng in 1645. The successors, his brother Li Zijing and nephew Li Guo, could not fight back and the dynasty ended in 1649 when Li Guo died in Nanning, Guangxi.

The Battle of Shanhai Pass, fought on May 27, 1644 at Shanhai Pass at the eastern end of the Great Wall, was a decisive battle leading to the beginning of the Qing dynasty rule in China proper. There, the Qing prince-regent Dorgon allied with former Ming general Wu Sangui to defeat peasant rebel leader Li Zicheng, founder of the short-lived Shun dynasty, allowing Dorgon and the Qing army to rapidly conquer Beijing.

The Southern Ming (Chinese: 南明; pinyin: Nán Míng), also known in historiography as the Later Ming (simplified Chinese: 后明; traditional Chinese: 後明; pinyin: Hòu Míng), officially the Great Ming (Chinese: 大明; pinyin: Dà Míng), was an imperial dynasty of China and a series of rump states of the Ming dynasty that came into existence following the Jiashen Incident of 1644. Peasant rebels led by Li Zicheng who founded the short-lived Shun dynasty captured Beijing and the Chongzhen Emperor committed suicide. The Ming general Wu Sangui then opened the gates of the Shanhai Pass in the eastern section of the Great Wall to the Qing banners, in hope of using them to annihilate the Shun forces. Ming loyalists fled to Nanjing, where they enthroned Zhu Yousong as the Hongguang Emperor, marking the start of the Southern Ming. The Nanjing regime lasted until 1645, when Qing forces captured Nanjing. Zhu fled before the city fell, but was captured and executed shortly thereafter. Later figures continued to hold court in various southern Chinese cities, although the Qing considered them to be pretenders.

The Nanjing regime lacked the resources to pay and supply its soldiers, who were left to live off the land and pillaged the countryside. The soldiers' behavior was so notorious that they were refused entry by those cities in a position to do so. Court official Shi Kefa obtained modern cannons and organized resistance at Yangzhou. The cannons mowed down a large number of Qing soldiers, but this only enraged those who survived. After the Yangzhou city fell in May 1645, the Manchus started a general massacre pillage and enslaved all the women and children in the notorious Yangzhou massacre. Nanjing was captured by the Qing on June 6 and the Hongguang Emperor was taken to Beijing and executed in 1646.

The transition from Ming to Qing, also known as the Manchu conquest of China or Ming-Qing transition, was a decades-long period of conflict between the Qing dynasty, established by the Manchu Aisin Gioro clan in Manchuria, and the Ming dynasty in China proper and later in South China. Various other regional or temporary powers were also involved in this conflict, such as the short-lived Shun dynasty. In 1618, before the start of the Qing conquest, Nurhaci, the leader of the Aisin Gioro clan, commissioned a document titled the Seven Grievances, in which he listed seven complaints against the Ming, before launching a rebellion against them. Many of the grievances concerned conflicts with the Yehe, a major Manchu clan, and the Ming's favoritism toward the Yehe at the expense of other Manchu clans. Nurhaci's demand that the Ming pay tribute to address the Seven Grievances was effectively a declaration of war, as the Ming were unwilling to pay money to a former vassal. Shortly thereafter, Nurhaci began to rebel against the Ming in Liaoning, a region in southern Manchuria.

At the same time, the Ming dynasty was struggling to survive amid increasing fiscal troubles and peasant rebellions. On April 24, 1644, Beijing fell to a rebel army led by Li Zicheng, a former minor Ming official who became the leader of the peasant revolt. Zicheng then proclaimed the Shun dynasty. At the time of the city's fall, the last Ming emperor, the Chongzhen Emperor, hanged himself on a tree in the imperial garden outside the Forbidden City. As Li Zicheng advanced toward him with his army, the general Wu Sangui, tasked by the Ming with guarding one of the gates of the Great Wall, swore allegiance to the Manchus and allowed them to enter China. Li Zicheng was defeated at the battle of Shanhai Pass by the combined forces of Wu Sangui and the Manchu prince Dorgon. On June 6, the Manchus and Wu entered the capital and proclaimed the young Shunzhi Emperor as the new Emperor of China.