2. Among all the great emperors in China, Li Shimin was in office for a short time, only 23 years from 626 to 649, but his achievements and reputation were no less than that of any entrepreneur in the history of China. In the words of Fan Wenlan in A Brief History of China, "Emperor Taizong ascended the throne and the Tang Dynasty flourished". Moreover, he was also a famous strategist and calligrapher, and his famous "Zhenguan Rule" in history pushed the feudal society of China to its peak.