New Recognitions about the Building Time of Ningxia County in the Ming Dynasty

Ningxia County was one of the nine frontiers in the Ming Dynasty and played a very important role in the defense of the northern border.There have been many descriptions about the time of its construction.After making a generalization of different descriptions,the article concludes that the formation of a complete military county not only had its standing military officer but also a stationary official and officer system and military defense area.Judging by such a standard,it proves that its formation was begun from Yongle to Xuande period and its final establishment was in the period of Zhengde in the Ming Dynasty.