Fang and Du Ruhui are the best among the eighteen bachelors in Qin Gong. Fang made great contributions to the changes of Xuanwu Gate. He suggested Li Shimin. He defected to Qin Wei a long time ago and has been dealing with things since he is good at planning and won the trust. He and Du Ruhui are known as "room for the end". After Li Shimin came to power, both of them helped Li Shimin to achieve a great deal of political achievements, initiated the rule of chastity, and laid the foundation for the prosperity of the Tang Dynasty when people's livelihood was depressed.

Li Shimin became a great monarch because of his personal qualities. He is very modest, because he has seen the collapse of the Sui Dynasty and the gradual demise of luxury countries caused by Emperor Yang Di. So he is frugal and sets an example. He used to be the aide of Prince Li, and once asked Li Jian to solve the problem. But Li Shimin didn't pay attention, but used Wei Zhi.

Wei Zhi is the only one who dares to say that about Li Shimin. After Wei Zhi's death, Li Shimin was also very sad. He said, as the old saying goes, you can dress with copper as a mirror, and you can know the rise and fall with history as a mirror. I lost Wei Zheng and a mirror. Li Shimin is really a magnanimous monarch. The earliest democratic thought.

At twelve o'clock in Chang 'an, you can also see how prosperous Chang 'an is, and there are many conference semifinals coming and going for business. There are many shops selling all kinds of things in the west market. Sesame was originally called flax because it was handed down from the Hu people. Cultural and material exchanges made the Tang Dynasty a metropolis with treasures from all sides. This is inseparable from the opening-up of the Tang Dynasty and Li Shimin's rule of Zhenguan.