Hongli was the fourth son of Emperor Yongzheng, and his biological mother was Niu Hulu. He was smart since he was a child and was deeply loved by his grandfather, Emperor Kangxi, who was brought into the palace to educate him personally. After Emperor Yongzheng came to the throne, he secretly appointed him as the crown prince. Emperor Yongzheng died suddenly in 1735, and the 25-year-old Hongli succeeded to the throne. He was changed to Qianlong the following year. He boasted of "combining leniency with severity", released imprisoned clan members, corrected some of the harsh policies of the Yongzheng Dynasty, and was praised by both the government and the public.
In the early and middle periods of Qianlong's reign, the country's national power reached its peak. He used troops in the northwest to pacify Junggar and Hezhuo, unified the Tianshan Mountains, and managed Tibet and pacified Jinchuan and Taiwan. He boasted of "ten perfect martial arts". The population exceeded 300 million around 1790, and business was booming. He went to the south of the Yangtze River six times and carried out large-scale construction projects, expanding the Old Summer Palace, the Summer Resort and building the Qingyi Garden. Culturally, he organized the compilation of the "Sikuquanshu", and at the same time borrowed and edited a large number of books, banned and destroyed them, causing more than a hundred literary inquisitions. Foreign trade was restricted to Guangzhou, and the request of the British Macartney Mission to expand trade was rejected.
In his later years, he was very fond of achievements, favored He Shen, and his administration was corrupted, and civil unrest occurred repeatedly in various places. In 1795, he proclaimed the title of Crown Prince to the fifteenth son of the emperor Yong Yan. The following year, he abdication and claimed to be the Retired Emperor, but he still held power by "training the government". In the first month of 1799, Hongli died in Yangxin Hall at the age of eighty-nine. His long reign and long life were rare among emperors in the past.
During the reign of Hongli, the Qing dynasty reached its peak, laying the foundation for the territory of modern China; the population and economic scale were unprecedented, and cultural projects such as the "Sikuquanshu" had far-reaching influence. However, in his later years, he was overjoyed in his achievements and squandered extravagantly. He favored He Shen, which led to the corruption of officialdom. He repeatedly set up literary prisons, borrowed, repaired, banned and destroyed classics, suppressing his ideological vitality. Externally, he adhered to the imperial system and closed himself off, missing the opportunity to understand the world. The crisis lurking under the prosperous age quickly emerged behind him.