Hall of mental cultivation in the Forbidden City was inscribed by which emperor?

Hall of mental cultivation in the Forbidden City was inscribed by Yong Zhengdi. Yong Zhengdi's ink "diligence" is a rare treasure in emperors' calligraphy. Yongzheng emperor's inscription "Diligent Sage" is located in the West Warm Pavilion in hall of mental cultivation, indicating that the emperor was strict with himself all his life. This rubbings are now in Luoyang Rubbings Museum.

Yong Zhengdi's style is famous for his hard work. Therefore, he took strong measures to deal with internal affairs and people's livelihood issues, such as setting up a military headquarters in the central government, strengthening the emperor by secret folding system, and implementing a series of policies in the local area to further increase the economy and national strength of the Qing Dynasty, such as leveling fields, returning fire to the people, returning fields to the country, cracking down on corrupt princes and ministers, and abolishing humble status.

Externally, through negotiations with Russia to determine the northern frontier of Mongolia, pacify Qinghai, and set up ministers stationed in Tibet to strengthen control over Tibet. However, at the same time, because its ruling period was in its prime, many reform measures were still affirmed by later generations and played an important role in the continuation of Kang Yong's prosperous period.