The collapse of the Ming Dynasty was a protracted affair, its roots beginning as early as 1600 with the emergence of the Manchu under Nurhaci. Originally a vassal of the Ming emperors, Nurhaci in 1582 embarked on an inter-tribal feud that escalated into a campaign to unify the Jianzhou Jurchen tribes. Later Nurhaci announced Seven Grievances and openly renounced the sovereignty of Ming overlordship in order to complete the unification of those Jurchen tribes still allied with the Ming emperor. With superior artillery the Ming were able to repeatedly fight off the Manchus, notably in 1623 and in 1628. However, they were not able to recapture their rule over the Manchus and the region. From 1629 onwards the Míng were wearied by a combination of internal strife and constant harassment of Northern China by the Manchu; who had turned to raiding tactics so as to avoid facing the Míng armies in open battle.
Unable to attack the heart of Míng directly, the Manchu instead bided their time, developing their own artillery and gathering allies. They were able to enlist Míng government officials as their strategic advisors. In 1633 they completed a conquest of Inner Mongolia, resulting in a large scale recruitment of Mongol troops under the Manchu banner and the securing of an additional route into the Míng heartland.
By 1636 the Manchu ruler Huang Taiji was confident enough to proclaim the Imperial Qing Dynasty at Shenyang, which had fallen to the Manchu by treachery in 1621, taking the Imperial title Chongde. The end of 1637 saw the defeat and conquest of Míng's traditional ally Korea by a 100,000 strong Manchu army, and the Korean renunciation of the Míng Dynasty.
On May 26, 1644, Beijing was sacked by a coalition of rebel forces led by Li Zicheng, a minor Ming official turned leader of the peasant revolt. The last Ming, Emperor Chongzhen committed suicide when the city fell, marking the official end of the dynasty. The Manchu Qing dynasty then allied with Ming Dyna...