What were the four counties in Hexi in Han Dynasty?

In the Han Dynasty, a large agricultural area was established in the north of the Great Wall, which was cultivated by settlers. In BC 12 1 year, Xie Kun, king of Xiongnu living in Hexi area, and King Xiutu surrendered to the Han Dynasty. In the Han Dynasty, Kun Xie was named as the source of Yin Hou, and four of his subordinates were named as Liehou. More than 40,000 people of its Ministry were placed in Longxi, Beidi, Shang Jun, Shuofang and Yun Yun, which are collectively called five subordinate countries. Subsequently, the Han Dynasty set up four counties in Hexi, the original nomadic areas of King Xie Kun and King Xiu Tu, namely Jiuquan, Wuwei, Dunhuang and Zhangye. According to History of Han Geography, in BC 104, the Western Han government established Jiuquan County and Zhangye County, in1kloc-0/year, Wuwei County, and in 88, Dunhuang County. According to the historical records of Emperor Wu of the Han Dynasty, in the second year of Yuanshou (before 12 1), the evil king fell, and his place was Wuwei and Jiuquan County. Ding Yuan for six years (former 1 1 1) was divided into Zhangye and Dunhuang counties. It is more reliable to refer to relevant historical materials.

Some scholars believe that the establishment of the four counties in Hexi has gradually changed Hexi region from a nomadic area to an agricultural area, which has a far-reaching impact on future generations. It separated the contact between nomadic Huns and Qiang people; At the same time, it also made the Han Dynasty form an alliance against the Huns with the agricultural country south of Tianshan Mountain and the nomadic Wusun in the Balkhash Lake area north of Tianshan Mountain. Later, the agricultural countries south of Tianshan surrendered to the Han Dynasty and merged into the territory of the Han Dynasty, which strengthened the strength of the Han Dynasty and weakened the influence of the Huns. Finally, this new agricultural belt connects the Central Plains agricultural belt with the agricultural area south of Tianshan Mountain. This facilitated the opening of the Silk Road in the future and played a very important role in the connection between the East and the West.