The Ming Great Wall (), built by the Ming dynasty (1368–1644), forms the most visible parts of the Great Wall of China today. A comprehensive archaeological survey, using advanced technology has concluded that the Ming walls measure from Jiayu Pass in the west to the sea in Shanhai Pass, then looping over to terminate in Manchuria at the Hushan Great Wall. This is made up of sections of actual wall, of trenches and of natural defensive barriers such as hills and rivers.
While the Ming walls are generally referred to as "Great Wall" (changcheng) in modern times, in Ming times they were called "border barriers" (邊牆; bianqiang) by the Chinese, since the term changcheng was said to evoke imagery of the tyranny of Qin Shi Huang (260–210 BC) and was associated with the Qin Great Wall.
History
Early Ming walls and garrisons
In 1368, the Hongwu Emperor (Zhu Yuanzhang, r.136898) ousted the Mongol-led Yuan dynasty from China to inaugurate the Ming dynasty. The Mongols fled back to Mongolia to form the Northern Yuan, but even after numerous campaigns, the Ming failed to expand further north and west.
In the early years of his reign, Hongwu envisioned a border policy where mobile armies along the northern frontier guarded the safety of China. To this end he set up the "eight outer garrisons" close to the steppe and an inner line of forts more suitable for defence. The inner line was the forerunner to the Ming Great Wall. In 1373, as Ming forces encountered setbacks, Hongwu put more emphasis on defence and adopted Hua Yunlong's (華雲龍) suggestion to establish garrisons at 130 passes and other strategic points in the Beijing area. More positions were set up in the years up to Hongwu's death in 1398, and watchtowers were manned from the Bohai Sea to Beijing and further onto the Mongolian steppes. These positions, however, were not for a linear defence but rather a regional one in which walls did not feature heavily, and offensive tactics remained the overarching policy at the time.
Hongwu's son, the Yongle Emperor (r.140224), continued his father's policy of active campaigning against the Mongols, and in 1421 moved the Ming capital from Nanjing in the south to Beijing in the north, partially to better manage the Mongol situation. Construction of walls in stone and earth began under Yongle's reign in strategic passes, when signal towers and ditch systems were also established. Yongle's reign also saw the rearrangement of the dynasty's frontiers that led to all but one of the eight outer garrisons being abolished to cut expenses, thereby sacrificing a vital foothold in the steppe transitional zone. After Yongle's death in 1424, the Ming abandoned the last garrison at Kaiping (the former Yuan capital also known as Shangdu) in 1430. The removal of these garrisons would have long-term consequences, as Ming foreign policy turned increasingly inward and defence became preferred over offence, especially after taking into consideration the cost to maintain the outlying garrisons.
Around 1442, a wall was erected by the Ming in Liaodong to protect Han settlers from a possible threat from the Jurched-Mongol Oriyanghan. In 146768, expansion of the wall provided further protection for the region from against attacks by the Jianzhou Jurchens in the northeast. An offshoot of the future main Great Wall line, this "Liaodong Wall" was of simple design: for the most part constructed by pouring mud between parallel rows of stakes, with moats dug on both sides, although stones and tiles were used in some parts.
Despite withdrawal from the steppe, the Ming military remained in a strong position until the Tumu Crisis in 1449, which caused the collapse of the early Ming security system. Over half of the campaigning Chinese army perished in the conflict, while the Mongols captured the Zhengtong Emperor Zhu Qizhen. This military debacle shattered the Ming dynasty military might and momentum that had given pause to the Mongols since the beginning of the dynasty, and the Ming were on the defensive from this point on.
In the immediate aftermath of the disaster, the most pressing political concern caused by the capture of the emperor was resolved when the acting Minister of War Yu Qian (the actual minister having died at Tumu) installed the Emperor's brother as the new Jingtai Emperor (r.14501459). Military tensions with the Oirats remained high during Jingtai's reign, as peace would have caused a great deal of political awkwardness for Jingtai and Yu Qian's faction, who benefited from putting Jingtai on the throne. To maintain a military presence while compensating for the loss of soldiers, fortifications, ditches, and ramparts were constructed in key passes, including at Zijing Pass (紫荊關; through where the Mongols had entered during the Tumu Crisis), Ningwu Pass (寧武關), and Juyong Pass. The work undertaken in this period marked a major shift toward defensive construction.
The Ordos Wall
The deterioration of the Ming military position in the steppe transitional zone gave rise to nomadic raids into Ming territory, including the crucial Ordos region, on a level unprecedented since the dynasty's founding. To solve this problem, the Ming could either go on the offensive and re-establish their positions in the steppe, or concede the transitional zones to the nomads and maintain a defensive and accommodative policy. Over the late 15th and 16th centuries, the choice between the two options became the subject of fierce debate in the Chinese court and dissension that was sometimes exploited by various political factions to get rid of the opposition. The decision to build the first major Ming walls was one of the outcomes of these debates as an acceptable compromise.
As offensive action against the nomads became increasingly untenable due to a shortage of fighting men and military supplies, Yu Zijun (余子俊; 14291489) first proposed constructing a wall in the Ordos region in August 1471, but this went against the traditional offensive-based policies in place since the early Ming. Minister of War Bai Gui (白圭) had tried to implement an offensive solution since taking office in 1467, and he objected to Yu's proposal because of cost fears. On 20December 1472, amid reports of people fleeing the frontier provinces due to the harsh military levies imposed to finance offensive campaigns, Yu reasoned that his wall project would not be as costly as the offensive strategy, and that the wall would be a temporary measure that would allow the Ming to restore its military and economic strength. The court and emperor approved the plan, and the 1473 victory in the Battle of Red Salt Lake (紅鹽池) by Wang Yue (王越) deterred Mongol invasions long enough for Yu Zijun to complete his wall project in 1474. This wall, a combined effort between Yu Zijun and Wang Yue, stretched from present day Hengcheng (橫城) in Lingwu (northwestern Ningxia province) to Huamachi town (花馬池鎮) in Yanchi County, and from there to Qingshuiying (清水營) in northeastern Shaanxi, a total of more than 2000 li (about ) long. Along its length were 800 strong points, sentry posts, beacon-fire towers, and assorted defences. 40,000 men were enlisted for this effort, which was completed in several months at a cost of over one million silver taels. This defence system proved its initial worth in 1482, when a large group of Mongol raiders were trapped within the double lines of fortifications and suffered a defeat by the Ming generals. This was seen as a vindication of Yu Zijun's strategy of wall-building by the people of the border areas. By the mid-16th century, Yu's wall in the Ordos had seen expansion into an extensive defence system. It contained two defence lines: Yu's wall, called the "great border" (大邊, dàbiān), and a "secondary border" (二邊, èrbiān) built by Yang Yiqing (14541530) behind it.
Following the success of the Ordos walls, Yu Zijun proposed construction of a further wall that would extend from the Yellow River bend in the Ordos to the Sihaiye Pass (四海冶口; in present-day Yanqing County) near the capital Beijing, running a distance of more than 1300 li (about ). The project received approval in 1485, but Yu's political enemies harped on the cost overruns and forced Yu to scrap the project and retire the same year. For more than 50 years after Yu's resignation, political struggle prevented major wall constructions on a scale comparable to Yu's Ordos project.
However, wall construction continued regardless of court politics during this time. The Ordos walls underwent extension, elaboration, and repair well into the 16th century.
The Walls of Xuanfu–Datong and the western reaches
With the Ordos now adequately fortified, the Mongols avoided its walls by riding east to invade Datong and Xuanfu, which were two major garrisons guarding the corridor to Beijing where no walls had been built. The two defence lines of Xuanfu and Datong left by the Northern Qi and the early Ming had deteriorated by this point, and for all intents and purposes the inner line was the capital's main line of defence. Starting from the 1520s, proposals were made to strengthen the defences of this region, but the plan was disrupted by the local populace's resistance to the prospect of labour; only in the 1540s did work proceed in earnest.
From 1544 to 1549, a defensive building program took place on a scale unprecedented in Chinese history. The project was led by Weng Wanda (翁萬達; 14981552), the Supreme Commander of the Xuan–Da defence area (宣大總督), which was responsible for the Xuanfu, Datong, and Shanxi areas. Troops were re-deployed along the outer line, new walls and beacon towers were constructed, and fortifications were restored and extended along both lines. Firearms and artillery were first mounted on the walls and towers around this time, for both defence and signalling purposes. The project's completion was announced in the sixth month of 1548, but the walls were steadily augmented for a time after that. At its height, the Xuan–Da portion of the Great Wall totalled about of wall, with some sections being doubled-up with two lines of wall, some tripled or even quadrupled. The outer frontier was now protected by a wall called the "outer border" (外邊, wàibiān) that extended from the Yellow River's edge at the Piantou Pass (偏頭關) along the Inner Mongolia border with Shanxi into Hebei province; the "inner border" wall (內邊, nèibiān) ran southeast from Piantou Pass for some , ending at the Pingxing Pass; a "river wall" (河邊, hébiān) also ran from the Piantou Pass and followed the Yellow River southwards for about . The Hebei section of the Great Wall was further fortified by planting trees along the wall.
As with Yu Zijun's wall in the Ordos, the Mongols shifted their attacks away from the newly strengthened Xuan–Da sector to less well-protected areas. In the west, Shaanxi province became the target of nomads riding west from the Yellow River loop. The westernmost fortress of Ming China, the Jiayu Pass, saw substantial enhancement with walls starting in 1539, and from there border walls were built discontinuously down the Gansu Corridor to Wuwei, where the low earthen wall split into two. The northern section passed through Zhongwei and Yinchuan, where it met the western edge of the Yellow River loop before connecting with the Ordos walls, while the southern section passed through Lanzhou and continued northeast to Dingbian. The origins and the exact route of this so-called "Tibetan loop" are still not clear.