The dynasty was founded by the Manchu Aisin Gioro clan in Manchuria. In the late sixteenth century, Nurhaci, originally a Ming vassal, began organizing "Banners" which were military-social units that included Manchu, Han, and Mongol elements. Nurhaci united Manchu clans and officially proclaimed the Later Jin dynasty in 1616. His son Hong Taiji began driving Ming forces out of the Liaodong Peninsula and declared a new dynasty, the Qing, in 1636. As Ming control disintegrated, peasant rebels led by Li Zicheng conquered the capital Beijing in 1644. Ming general Wu Sangui refused to serve them, but opened the Shanhai Pass to the Banner Armies led by the regent Prince Dorgon, who defeated the rebels and seized the capital. Dorgon served as Prince regent under the Shunzhi Emperor. Resistance from the Ming loyalists in the south and the Revolt of the Three Feudatories led by Wu Sangui delayed the complete conquest until 1683 under the Kangxi Emperor (1661–1722). The Ten Great Campaigns of the Qianlong Emperor from the 1750s to the 1790s extended Qing control into Inner Asia. During the peak of the Qing dynasty, the empire ruled over the entirety of today's Mainland China, Hainan, Taiwan, Mongolia, Outer Manchuria and Outer Northwest China. The early Qing rulers maintained their Manchu customs, they were patrons of Tibetan Buddhism, and while their title was Emperor, used "Bogd khaan" when dealing with the Mongols. They governed using a Confucian style and bureaucratic institutions, retaining the imperial examinations to recruit Han Chinese to work under or in parallel with the Manchu rulers. They also adapted the ideals of the Chinese tributary system in asserting superiority over peripheral countries such as Korea and Vietnam, while annexing neighboring territories such as Tibet and Mongolia.