The Great Wall of China is a series of fortifications that were built across the historical northern borders of ancient Chinese states and Imperial China as protection against various nomadic groups from the Eurasian Steppe. Several walls were built from as early as the 7th century BC, with selective stretches later joined together by Qin Shi Huang (220–206 BC), the first emperor of China. Little of the Qin wall remains. Later on, many successive dynasties built and maintained multiple stretches of border walls. The best-known sections of the wall were built by the Ming dynasty (1368–1644).
Apart from defense, other purposes of the Great Wall have included border controls, allowing the imposition of duties on goods transported along the Silk Road, regulation or encouragement of trade and the control of immigration and emigration. Furthermore, the defensive characteristics of the Great Wall were enhanced by the construction of watchtowers, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and the fact that the path of the Great Wall also served as a transportation corridor.
The frontier walls built by different dynasties have multiple courses. Collectively, they stretch from Liaodong in the east to Lop Lake in the west, from the present-day Sino–Russian border in the north to Tao River (Taohe) in the south; along an arc that roughly delineates the edge of the Mongolian steppe; spanning over 20,000 km (12,000 mi) in total. Today, the defensive system of the Great Wall is generally recognized as one of the most impressive architectural feats in history.
ENCYCLOPEDIC ENTRY
The one thing most people “know” about the Great Wall of China—that it is one of the only man-made structures visible from space—is not actually true. Since the wall looks a lot like the stone and soil that surround it, it is difficult to discern with the human eye even from low Earth orbit, and is difficult to make out in most orbital photos. However, this does not detract from the wonder of this astounding ancient structure.
For millennia, Chinese leaders instituted wall-building projects to protect the land from northern, nomadic invaders. One surviving section of such an ancient wall, in the Shandong province, is made of hard-packed soil called “rammed earth” and is estimated to be 2,500 years old. For centuries during the Warring States Period, before China was unified into one nation, such walls defended the borders.
Around 220 B.C.E., Qin Shi Huang, also called the First Emperor, united China. He masterminded the process of uniting the existing walls into one. At that time, rammed earth and wood made up most of the wall. Emperor after emperor strengthened and extended the wall, often with the aim of keeping out the northern invaders. In some places, the wall was constructed of brick. Elsewhere, quarried granite or even marble blocks were used. The wall was continuously brought up to date as building techniques advanced.
Zhu Yuanzhang, who became the Hongwu Emperor, took power in 1368 C.E. He founded the Ming Dynasty, famous for its achievements in the arts of ceramics and painting. The Ming emperors improved the wall with watchtowers and platforms. Most of the familiar images of the wall show Ming-era construction in the stone. Depending on how the wall is measured, it stretches somewhere between 4,000 and 5,500 kilometers.
In the 17th century, the Manchu emperors extended Chinese rule into Inner Mongolia, making the wall less important as a defense. However, it has retained its importance as a symbol of Chinese identity and culture. Countless visitors view the wall every year. It may not be clearly visible from space, but it is considered “an absolute masterpiece” here on Earth.
History of construction
The Great Wall developed from the disparate border fortifications and castles of individual Chinese kingdoms. For several centuries these kingdoms probably were as concerned with protection from their near neighbours as they were with the threat of barbarian invasions or raids.
Early building
About the 7th century BCE the state of Chu started to construct a permanent defensive system. Known as the “Square Wall,” this fortification was situated in the northern part of the kingdom’s capital province. From the 6th to the 4th century other states followed Chu’s example. In the southern part of the Qi state an extensive perimeter wall was gradually created using existing river dikes, newly constructed bulwarks, and areas of impassable mountain terrain. The Qi wall was made mainly of earth and stone and terminated at the shores of the Yellow Sea. In the Zhongshan state a wall system was built to thwart invasion from the states of Zhao and Qin in the southwest. There were two defensive lines in the Wei state: the Hexi and Henan walls. The Hexi Wall was a fortification against the Qin state and western nomads. Built during the reign of King Hui (370–335 BCE), it was expanded from the dikes on the Luo River on the western border. It started in the south near Xiangyuan Cave, east of Mount Hua, and ended at Guyang in what is now the Inner Mongolia Autonomous Region. Henan Wall, built to protect Daliang , was repaired and extended in King Hui’s later years. The Zheng state also built a wall system, which was rebuilt by the Han state after it conquered Zheng. The state of Zhao completed a southern wall and a northern wall; the southern wall was built mainly as a defense against the Wei state.
After administrative reorganization was carried out by Shang Yang (died 338 BCE), the Qin state grew politically and militarily to become the strongest among the seven states, but it was frequently raided by the Donghu and Loufan, two nomadic peoples from the north. Therefore, the Qin erected a wall that started from Lintiao, went north along the Liupan Mountains, and ended at the Huang He In the Yan state two separate defensive lines were prepared—the Northern Wall and the Yishui Wall—in an effort to defend the kingdom from attacks by northern groups such as the Donghu, Linhu, and Loufan, as well as by the Qi state in the south. The Yishui Wall was expanded from the dike of the Yi River as a defense line against Qi and Zhao, its two main rival states. It began southwest of Yi City, the capital, and ended south of Wen’an. In 290 BCE the Yan state built the Northern Wall along the Yan Mountains, starting from the northeast in the area of Zhangjiakou in Hebei, passing over the Liao River, and extending to the ancient city of Xiangping . This was the last segment of the Great Wall to be erected during the Zhanguo period.
In 221 BCE Shihuangdi, the first Qin emperor, completed his annexation of Qi and thus unified China. He ordered removal of the fortifications set up between the previous states because they served only as obstacles to internal movements and administration. In addition, he sent Gen. Meng Tian to garrison the northern border against incursions of the nomadic Xiongnu and to link the existing wall segments in Qin, Yan, and Zhao into the so-called “10,000-Li Long Wall” . This period of construction began about 214 BCE and lasted a decade. Hundreds of thousands of soldiers and conscripted workers laboured on the project. With the fall of the Qin dynasty after Shihuangdi’s death, however, the wall was left largely ungarrisoned and fell into disrepair.
