Shanhai Pass in the context of "Wu Sangui"

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.

Manchuria is a historical region in northeast Asia encompassing the entirety of present-day northeast China and parts of the modern-day Russian Far East south of the Uda River and the Tukuringra-Dzhagdy Ranges. The exact geographical extent varies depending on the definition: in the narrow sense, the area constituted by three Chinese provinces of Heilongjiang, Jilin, and Liaoning as well as the eastern Inner Mongolian prefectures of Hulunbuir, Hinggan, Tongliao, and Chifeng; in a broader sense, historical Manchuria includes those regions plus the Amur river basin, parts of which were ceded to the Russian Empire by the Manchu-led Qing dynasty during the Amur Annexation of 1858–1860. The parts of Manchuria ceded to Russia are collectively known as Outer Manchuria or Russian Manchuria, which include present-day Amur Oblast, Primorsky Krai, the Jewish Autonomous Oblast, the southern part of Khabarovsk Krai, and the eastern edge of Zabaykalsky Krai.

The name Manchuria is an exonym (derived from the endonym "Manchu") of Japanese origin. The history of "Manchuria" (Manzhou) as a toponym in China is disputed, with some scholars believing it was never used while others believe it was by the late 19th century. The area was historically referred to by various names in the Qing dynasty such as Guandong (East of the Pass) or the Three Provinces referring to Fengtian (Liaoning), Heilongjiang, and Jilin. Manchuria as a geographical term was first used in the 18th or 19th centuries by the Japanese before spreading to Europe. The term was promoted by the Empire of Japan in support for the existence of its puppet state, Manchukuo. Although the toponym is still used, some scholars treat the term with caution or avoid it altogether due to its association with Japanese colonialism. The term is deprecated in China due to its association with Japanese imperialism and ethnic connotations. As a result, areas once considered part of Manchuria are simply referred to as the Northeast. The Three Provinces and the Northeast were also in concurrent use among the Japanese along with Manchuria until the Mukden incident of 1931.

China proper, also called Inner China or Han China, are terms used primarily in the Western world in reference to the traditional "core" regions of Chinese civilization centered around the Yellow River and Yangtze River valleys. There is no fixed definition for China proper as many administrative, cultural and territorial shifts have occurred throughout history. One definition refers to the original heartland regions of the Chinese civilization, the Central Plain (southern North China Plain around the lower Yellow River valley) as well as the historical Nine Provinces; another to the Eighteen Provinces inside Shanhai Pass designated by the Qing regime. In contrast, Outer China is a term usually includes the peripheral marchland regions such as Gobi Desert,, Tarim Basin, Northeast China, Dzungaria, Tibetan Plateau and Yungui Plateau, which were historically autonomous regions with unstable allegiance to the authority of Chinese monarchs.

The term was first used by the Europeans during the 17th century to distinguish the historical "Han lands" (Chinese: 漢地, i.e. regions long dominated by the majority Han Chinese population) from "frontier" regions of China where Han populations intermix with other indigenous ethnicities (e.g. Turkic peoples such as Uyghurs, Kazakhs and Uzbeks, Mongolic peoples, and Tibeto-Burmese peoples such as Tibetans, Yi and Bai) and newer foreign immigrants (e.g. Slavic colonists such as Russians and Ukrainian Cossacks), sometimes known as "Outer China". There was no direct translation for "China proper" in the Chinese language at the time due to differences in terminology used by the Qing regime to refer to the regions.

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.