The Defense Engineering System of the Great Wall

The defense engineering system of the Great Wall: The Great Wall stretching thousands of miles is not just a single wall but a complete defensive system composed of many defense equipment including walls, watch

towers, fortresses and beacon towers. The defensive system was controlled by all levels of the military chain of command. Taking the Great Wall of the Ming Dynasty as an example, nine military jurisdictional areas including Liaodong, Datong, Yulin, Ningxia, and Gansu were established on the Great Wall for defense and maintenance of the Great Wall, ranging from the Yalu River in the east and Jiayuguan in the west. Therefore, the nine military jurisdictional areas were called the "nine major defensive areas," with a chief military officer taking charge of defending each section of the Great Wall or supporting the adjacent regions. There were about a million soldiers guarding along the Great Wall in the Ming Dynasty. The military chief normally lived and worked inside the cities and other officials at all levels were stationed in the watch towers and fortresses in defense areas, campsites and walls.