Ancient Section of the Great Wall

From as early as the seventh century B.C.E., Chinese kingdoms built walls along their northern frontiers to defend themselves against the forays of savage Hun (Xiongnu) nomadic tribes.  In 120 B.C.E., during the reign of Emperor Wu (147-87 B.C.E.) of the Western Han dynasty, the most comprehensive Great Wall project to date was initiated, with up to four systems of fortification spanning the breadth of China from Dunhuang in the west to the Korean peninsula in the east.  Part of this Great Wall was constructed across the mouth of the Hexi Corridor from Dunhuang’s Yumenguan (Jade Gate Pass) in the west to Jiayuguan, 180 miles to the east.  Three years later in 117 B.C.E., Dunhuang was appointed a prefecture.  For the next millennium, it remained one of China’s most important command posts with heavy concentrations of military and civilian personnel.