The Qianlong Emperor, also known by his temple name Emperor Gaozong of Qing, personal name Hongli, was the fifth emperor of the Qing dynasty and the fourth Qing emperor to rule over China proper. He reigned officially from 1735 until his abdication in 1796, but retained ultimate power subsequently until his death in 1799, making him one of the longest-reigning monarchs in history as well as one of the longest-lived.

Throughout Chinese history, "Emperor" was the superlative title held by the monarchs who ruled various imperial dynasties. In traditional Chinese political theory, the emperor was the "Son of Heaven", an autocrat with the divine mandate right to rule all under Heaven. Emperors were worshiped posthumously under an imperial cult. The lineage of emperors descended from a paternal family line constituted a dynasty, and succession in most cases theoretically followed agnatic primogeniture.