The eight square city is located in the purple, white, black and Xuanguo, the gathering place of the four countries. There are numerous businessmen and it is a luxurious city outside the Great Wall. Among the people, there is also a popular saying: "the horsemen of the eight square city are all dressed in silk and silk, and the servant girls all know the music, chess, calligraphy and painting." There is always a basis for rumors. From this sentence, we can hear that the city of Bafang is rich in oil. And its terrain is very dangerous. It's easy to defend and hard to attack. It used to be an...