According to legend, when King Hui of Qin built Chengdu, Zhang Yi said, "The city has been broken repeatedly, so it can't stand. Suddenly, a big turtle came out of the river, and Zhou Xing spun up. Witch words: if you build it according to the turtle's line, the city will stand. " So Chengdu was also called "Turtle City" in ancient times. In ancient times, dragons, phoenixes, turtles and forests were collectively called the Four Spirits, and the name "Turtle City" was not disrespectful at that time. On the contrary, it implied that there were gods to protect and evaluate.

From the end of the Spring and Autumn Period to the beginning of the Warring States Period, after entering the area west of the Three Gorges, the Ba people gradually conquered and integrated the indigenous peoples in the Yangtze River, Wujiang River and Jialing River basins, and controlled a large area connecting Hanzhong in the north, Qianfu in the Antarctic, Fengjie in the east and Yibin in the west. With the downtown area of Chongqing as the center, they established a country with a vast territory, many nationalities and rich products, which was called "Ba State" in history.

Regarding the capital of Pakistan, Huayang Guozhi said: "Although Bazi was the capital of Jiangzhou, he ruled Dianjiang or Pingdu, and later he ruled Langzhong." Jiangzhou is the urban area of Chongqing today, Dianjiang is Hechuan today, Pingdu is Fengdu today, and Langzhong is the same in ancient and modern times. Why do Pakistanis keep changing the location of the capital? This can be explained by the historical connotation that the Ba people marched westward from the Three Gorges of the Yangtze River and finally retreated to Langzhong and their country died. That is to say, the Ba people first moved westward from Fengjie, and once founded their country in Fengdu today. Later, due to the continuous advance of Chu's forces, they were forced to move westward to Chongqing today and build their capital here.

In addition to the documentary records, the cultural relics unearthed underground are a kind of evidence for the Ba people to build their capital in Chongqing today. Not to mention, in the mid-1980s, archaeologists cleared up and unearthed Ba bronze weapons belonging to the Warring States Period in Qiansi Gate, Yuzhong District, including willow swords, crossbows and arrows. The more important discovery was made in the early 1950s when chengdu-chongqing railway was built. At that time, more than 20 boat coffins with the characteristics of Ba culture were unearthed in Dongsunba, Jiulongpo District. The canoe-shaped coffins were dug with whole pieces of wood, and bronze weapons and swords were: graupel, spear, ge and so on. It can now be inferred that the tomb group of the ship coffins of Dongsunba was the cemetery of the soldiers and officials who guarded the west gate of Badu in those days.

In the middle and late Warring States period, due to the continuous westward advance of Chu's forces, a situation of "Jiangzhou is east, and its people are half Chu" was formed. The monarch and ministers of Pakistan had no choice but to move the capital to the northwest, first stationed in Hechuan, later called Dulangzhong, and finally destroyed Qin in 3 16 BC.