Ming Great Wall Construction System

Timeline

1. 1370–1380Shanxi and Beiping (modern Hebei) borderlands · North ChinaIn the early Hongwu reign, passes and beacon towers were added along the old northern Great Wall in Shanxi and Beiping (modern Hebei), with generals garrisoned there; together with the Datong and Xuanfu guards, this formed the first line of defense on the Ming northern frontier.
2. 1381–1390Full length of the Ming northern frontier · North ChinaFrom the fourteenth year of Hongwu, Xu Da and others were dispatched to lead large-scale wall-building along the frontier, adding passes, beacon towers, and ramparts, linking late-Yuan old fortifications with newly built sections into a single system; over the following years it was progressively completed, with brick-and-stone facing and standardized beacon tower spacing standardized.
3. 1403–1567Along the Nine Frontier Garrisons · North ChinaAfter the Yongle relocation of the capital, emphasis was placed on strengthening the capital's outer perimeter; during the Jiajing reign, under the threat of Altan Khan, the Great Wall was extensively faced in brick, producing the brick-and-stone sections seen today at Juyong Pass and Badaling, forming in-depth defense together with the Nine Frontier Garrisons, beacon towers, and watchtowers.