Abstract:
In the 21st of Emperor of Xuanzong’s Reign Title of Kaiyuan, the ten military governorships were publicly founded, of which the military governors of Hexi, Longyou and Shuofang obtained the most important military status. This was for three reasons: geographic composition, changes in system and military action. Geographically, since the introduction of Yuwen Tai’s “Guanzhongbased policy”, the focus of military defense had been located in northwestern China. Then, for changes in system, the decline of the system of prefectural military commands made it necessary to introduce the system of military towns and military governorships, which provided a systematic guarantee for the important status of the three military governors. Finally, the important status of the three military governors resulted necessarily from military actions in the early Tang Dynasty (prior to the 21st of the Reign Title of Kaiyuan).
