Great Wall of China

The Chinese were already familiar with the techniques of wall-building by the Spring and Autumn period, between the 8th and 5th centuries BCE. In that period and the Warring States period that followed, the states of Zheng, Chu, Qin, Wei, Zhao, Qi, Lu, Han, Yan, Zhongshan and Zhou all built extensive fortifications to defend their own borders. Made to withstand small arms such as swords and spears, these walls were mostly of stone or of earth and gravel stamped between board frames. The first walls of what became the Great Wall date to the 7th century BCE.

The state of Qin emerged victorious in 221 BCE. Its ruler, now the First Emperor of a unified China, meant to centralise rule and prevent the return of the feudal lords, and so ordered the destruction of the walls that divided his empire among the former states. To guard against the Xiongnu people of the north, however, he had new walls built to connect the remaining fortifications along the northern frontier. “Build and move on” was a central guiding principle, implying that the builders were not erecting a permanently fixed border. The historian Sima Qian, in his Records of the Grand Historian, used the term “Long Wall” both for the separate walls of the Warring States and for the First Emperor’s more unified construction.

No formal definition of what makes up a “Great Wall” has been agreed, and its defensive lines include stretches of rampart, trenches, ditches and individual fortresses. Taken together, the fortifications run from Liaodong in the east to Lop Lake in the west and from the present-day Sino-Russian border in the north to the Tao River in the south, an arc that roughly follows the edge of the Mongolian steppe. In 2012 the National Cultural Heritage Administration counted 10,051 wall sections, 1,764 ramparts or trenches, 29,510 individual buildings and 2,211 fortifications or passes, with walls and trenches totalling 21,196.18 km; the Ming wall alone measures 8,850 km.

The Ming wall begins at Jiayu Pass in Gansu, runs down the Hexi Corridor and across the Ordos Desert, and at Piantou Pass in Shanxi splits into an Outer and an Inner Great Wall, which join again near Beijing; it ends at Shanhai Pass on the Bohai Gulf, the “First Pass Under Heaven”. Watchtowers, troop barracks, garrison stations and signals of smoke or fire made it a system of defence. It also served as a transport corridor and as a means of border control, regulating migration and trade and levying duties on goods carried along the Silk Road.

Because moving large quantities of material was difficult, the builders used what lay to hand: stone in the mountains and rammed earth on the plains, together with wood. The Han, the Northern dynasties and the Sui repaired, rebuilt or extended sections at great cost, and dynasties founded by non-Han peoples, the Xianbei-ruled Northern Wei, the Khitan-ruled Liao, the Jurchen-led Jin and the Tangut-established Western Xia, built border walls of their own further north. The Tang and Song made no significant effort in the region.

The Ming made the largest contribution. After their defeat by the Oirats at the Battle of Tumu, amid long conflict with Mongol tribes, they adopted a strategy of walls along the northern border, following the southern edge of the Ordos Desert. Their walls were stronger and more elaborate, of brick and stone instead of rammed earth: bricks were easier to work and bore more weight, cut stone was used for foundations, edges and gateways, and bricks were bound with a mortar of sticky rice soup and slaked lime. Up to 25,000 watchtowers are estimated to have been built, and under general Qi Jiguang 1,200 were raised between Shanhaiguan Pass and Changping in 1567–1570, while sections of the rammed-earth wall were faced with brick. At Juyong Pass, near Beijing, the wall stands 7.8 m high and 5 m wide.

Because of the wall’s association with the First Emperor’s supposed tyranny, later dynasties usually avoided calling their own additions the “Long Wall”, preferring words such as frontier, rampart, barrier or border wall; poetic names included the Purple Frontier and the Earth Dragon. The longer name “Ten-Thousand Mile Long Wall” goes back to Sima Qian’s description, although “ten-thousand” is figurative and means innumerable. Only during the Qing period did “Long Wall” become the catch-all term for the many border walls, equivalent to the English “Great Wall”.

None of the Europeans who visited China or Mongolia in the 13th and 14th centuries, among them William of Rubruck and Marco Polo, mentioned the wall. Ibn Battuta, in China c. 1346, had heard of it and linked it to the wall the Qur’an says Dhul-Qarnayn built against Gog and Magog, but found no one who had seen it. After the Portuguese reached Ming China in the early 16th century accounts of it reached Europe, among them Gaspar da Cruz’s treatise of 1559 and João de Barros’s Asia of 1563, and in 1605 the Jesuit brother Bento de Góis entered China at Jiayu Pass. Early European accounts were mostly modest and empirical, but later ones slid into hyperbole, including the false claim that the Ming walls were those of the First Emperor.

Most of the ancient walls have eroded away over the centuries, and no surviving records give the exact length and course of the Qin walls. Towards the end of the Ming the wall helped hold back the Manchus at the heavily fortified Shanhai Pass, until in 1644, after Beijing had fallen to Li Zicheng’s Shun dynasty, the general Wu Sangui opened its gates to them. Under the Qing, whose borders reached beyond the wall with the annexation of Mongolia, work on it for border defence was discontinued, though projects such as the Willow Palisade continued.

Portions north of Beijing and near tourist centres have been preserved and even extensively renovated, but elsewhere the wall is in disrepair. It has served as a source of stone for houses and roads, been marked with graffiti, and lost inscribed bricks to the market; parts have been destroyed for construction or mining. A 2012 report found that 22% of the Ming wall, or 1,961 km, has disappeared, and in 2007 it was estimated that more than 60 km in Gansu may disappear within 20 years through erosion by sandstorms. A 2014 repair with concrete near the border of Liaoning and Hebei was much criticised, and in 2023 workers in Shanxi widened a gap for an excavator, causing what police called “irreversible damage”. Surveys still add to it: in 2009, 180 km of unknown Ming wall were found with infrared range finders and GPS devices.

When China opened its borders to foreign merchants and visitors after its defeat in the First and Second Opium Wars, the wall became a main attraction for tourists, and the travelogues of the later 19th century enhanced its reputation and its mythology. Badaling, the first section opened to the public in the People’s Republic of China and the one shown to foreign dignitaries, saw nearly 10 million visitors in 2018, and a daily limit of 65,000 visitors was set in 2019. The wall is a UNESCO World Heritage Site, was voted one of the New 7 Wonders of the World in 2007, and is recognised as one of the most impressive architectural feats in history. By the 19th century “the Great Wall of China” had become the standard name in English and French.

One lasting legend holds that the wall can be seen from space. The claim that it is visible from the Moon appears as early as a letter of 1754 by the English antiquary William Stukeley and in Ripley’s Believe It or Not! in 1932, but it is false: seen from the Moon, the wall would look as wide as a human hair viewed from 3 km away. NASA states that from low Earth orbit it is barely visible, and only under nearly perfect conditions, and China’s first astronaut, Yang Liwei, stated that he had not been able to see it.