Why did the Northern Wei Dynasty take Pingcheng Datong as its capital?

In the first year of Tianxing in the Northern Wei Dynasty (398), Tuoba GUI moved from Lesheng (now Helinger, Inner Mongolia) to Pingcheng (now Dongwuli Gucheng Village, Datong City). During the period of moving the capital, Datong called Sizhou the capital of Pingcheng. "Shu Wei Ji Xu" contains: Mu Di six years, "The city is prosperous and happy as the northern capital, and Pingcheng is the southern capital." In the first year of Tianxing, "in autumn and July, we moved the capital to Pingcheng, and began to build palaces, ancestral temples and establish the country". In September of the seventh year of Emperor Taizong (422), Emperor Taizong wrote: "Build a Guo outside the city and go back 32 miles a week." In the 18th year of Taihe (494), after Luoyang was established as its capital, Pingcheng was ruled by Zhou Huan and Dai Jun. Zhou Huan has jurisdiction over 8 counties 14 counties. In 1997, the capital of the Northern Wei Dynasty was Datong, which experienced six emperors: Daowudi, Ming Yuan Di, Taiwudi, Wen Chengdi, Xianwendi and Xiaowen. According to the construction scale of the Northern Wei Dynasty, at its peak, the population of Daidu Pingcheng exceeded 6.5438+0 million. During the reign of Xiaochang (525 ~ 527), there were frequent wars in Pingcheng, and the people scattered and abandoned them.

In the seventh year of Tianbao in the Northern Qi Dynasty (556), Beihengzhou was changed to Heng 'an Town, also known as Dongzhou City, which belonged to Taiping County of Hengzhou (30 miles west of Datong, also known as Xicheng). The following year, the town was abandoned, and it was still Beihuan State.

At the beginning of the Northern Zhou Dynasty (577), Yu Wenxuan destroyed the Northern Qi Dynasty and changed Taiping County to Yunzhong County, which belonged to Beishuozhou. Heng 'an Town belongs to Yunzhong County, Shuozhou.

In the first year of Emperor Kai of Sui Dynasty (58 1), Yunzhong County was Yunnei County. In the second year of Daye (606), Shuozhou was changed to Mayi County, and Heng 'an Town was subordinate to Yunnei County of Mayi County.

Beihengzhou was established in the sixth year of Tang Wude (623) and abolished in the seventh year (624). In the 14th year of Zhenguan (640), Xiang County was established (moved from Dingxiang City in the north of Shuozhou), and Yunzhou was also ruled (moved from Inner Mongolia and Linger). In the first year of Yongchun (682), it was destroyed by the desert water of East Turkistan, and the counties were abolished, and the people moved to Shuozhou. In the 18th year of Kaiyuan (730), Dingxiang was changed to Yunzhong County and Yunzhou was restored. In the first year of Tianbao (742), Yunzhou was changed to Yunzhong County. In the first year of Gan Yuan (758), it was changed to Yunzhou. In the 10th year of Xian Tong (869), the Datong Army was appointed as our time.