Yinzhen is the fourth son of Emperor Kangxi and his biological mother is De Fei Wu Ya. In his early years, he accompanied his father on tours and handled errands. In 1709, he was awarded the title of Prince Yong. He had already been given a garden to the north of Changchun Garden, which later became the Old Summer Palace. While the princes were vying for the throne, he was indifferent on the surface and lived by paying homage to Buddha and studying. He called himself "Pochen Lay Scholar" and secretly recruited Long Keduo, the commander of the infantry, Nian Gengyao, the governor of Sichuan and Shaanxi, and others. Emperor Kangxi died of illness in 1722, and Long Keduo announced his will to be succeeded by Yinzhen. Due to the hasty succession process, there has long been a rumor among the people that he tampered with the imperial edict, but there is a lack of reliable evidence.
After taking the throne, he successively imprisoned and attacked political opponents such as Yin Si and Yinzhen, and punished Nian Gengyao and Long Keduo who were proud of their merits. He established a secret reserve system, established a military aircraft office, expanded the scope of secret memorials, and concentrated imperial power unprecedentedly. In terms of finance, we promoted the diversion of land into acres, the return of fire consumption to the public, and the raising of honest silver, and investigated the money and food deficits in various places; in the southwest, we promoted the return of land to locals, deployed troops in Qinghai and Junggar in the northwest, and signed the Kyaktu Treaty with Russia to delineate the middle section of the border between China and Russia.
Yinzhen was diligent in government affairs, often reviewing memorials until late at night, and left a large number of inscriptions. He personally tried Zeng Jing's case, promulgated the "Dayi Jue Mi Lu", and also established a literary inquisition. After more than ten years of rectification, the national silver inventory increased from about 8 million taels in the late Kangxi years to a peak of more than 60 million taels. In August 1735, he died suddenly in the Old Summer Palace, which was said to be related to taking elixirs. He was succeeded by the fourth son of the emperor, Hongli, and was buried in Tailing.
Yinzhen was one of the most diligent and controversial emperors in the Qing Dynasty. He used vigorous and resolute means to check the deficit, rectify the administration of officials, and implement reforms such as apportionment of land into acres, return of fire consumption to the public, and return of land to rivers, etc., which enriched the treasury, strengthened the central government's governance of the southwest, built on the past and forged ahead, and laid the foundation for the prosperity of the Qianlong Dynasty. However, he was harsh and ungrateful to his political opponents and heroes. The military and secret system brought the monarchy to its peak, and the literary prison became more severe. The doubtful case of his succession also made him suffer a long-term infamy after his death.