What was the purpose of the Great Wall during the Qin and Han dynasties?

During the Qin dynasty, the primary purpose of the Great Wall was to fortify the northern border against incursions by the nomadic Xiongnu people. Following the unification of China, Emperor Shihuangdi ordered the connection of existing regional wall segments into a unified defensive system, which was garrisoned by troops under General Meng Tian.12

During the Han dynasty, the wall’s function expanded beyond simple defense. While it continued to be strengthened as part of military campaigns against the Xiongnu, it also served to:

• Centralize control: The wall helped the state regulate and manage trade and travel.3
• Support economic growth: It contributed to the development of farmland in northern and western China and facilitated the expansion of the Silk Road trade network.3

To maintain these functions, the Han established a sophisticated system of strongpoints along the wall, including beacons, towers, forts, and castles.3