The Establishment of Northwest Frontier Fortress in the Han Dynasty

This paper is to consider,from the perspective of the frontier defense,the establishment of the northwest frontier fortress during the Han Dynasty.The research shows that the frontier fortress,begun under the rule of Emperor Wu of Han Dynasty,remains unchanged during the periods of Emperor Zhao and Emperor Xuan.It is up to the Eastern Han Dynasty,the establishment of frontier fortress enters a new stage of development.The constructions are changing according to the situations.On the walls and the surroundings of the establishments,there are shooting and observation devices,as well as security and guarding facilities.As the frontier's basic unit,it is closely associated with the beacon towers.Its functions are to keep a lookout on the enemy,transmit information,station armies,resist frontier invaders,guard against thieves,crack down criminals,etc.,which are of great significance to the military mission.