Great Wall of China

May 20, 2000

It's more than 2,000 years old, but the Great Wall of China remains one of the great wonders of the world, an engineering feat rarely matched in the 22 centuries since its construction began.

Stretching 4,500 miles, from the mountains of Korea to the Gobi Desert, it was first built to protect an ancient Chinese empire from marauding tribes from the north. But it evolved into something far greater - a boon to trade and prosperity and ultimately a symbol of Chinese ingenuity and will. 

The truth is, though, that the Great Wall is actually a series of walls built and rebuilt by different dynasties over 1,000 years. And while they often served the same purpose, these walls reflected the worlds - both natural and cultural - in which they were erected. For all its seeming timelessness, the Great Wall is an emblem of China's evolution. 

The first section of the Great Wall took 10 years to build - at the rate of about one mile per day. 

Qin Dynasty

China's first emperor was its first Great Wall builder. He was also a relentless book-burner and a ruler who sent free thinkers to work - and often to die - on his wall. See more about him. 

The oldest section of the Great Wall was begun in 221 B.C., not long after China was unified into an empire from a loose configuration of feudal states. The first Chinese emperor, Qin Shi Huang, restored the ruins of older walls and linked them with new construction to create a massive 3,000-mile-long fortification meant to protect China's northern frontiers against attack by marauding nomads. 

But Qin Shi Huang was no benevolent ruler looking out for his people. He was a staggeringly repressive tyrant who tried to standardize human thought in the same way he standardized laws, weights and measures. His followers believed that people were inherently evil and needed to live by a strict set of rules. So they burned most of the Confucian literature in the country, believing that it encouraged free thinking. In fact, the emperor made nonconformist thought a capital offense and sentenced thousands of intellectuals to years of forced labor on the Great Wall. 

The harsh Qin (pronounced Chin) regime thought its strict rules regarding Chinese life would allow the dynasty to last for generations. But that was not to be. In 209 B.C., just one year after the emperor's death, an army of peasants, bristling under decades of oppression, rose up in revolt. Provincial officials, knowing they'd be executed for merely reporting the rebellion, kept silent. When the central government finally learned of the uprising, it was too late. In the end, Qin Shi Huang's brief dynasty fell victim to the fear and mistrust bred by its own despotic excesses. 

Secrets of the Qin Wall

As the wall inched across the Chinese wilderness, its builders were forced to rely upon local materials. Much of the Qin wall was built with dry-laid native stone, but where stone was  scarce, engineers built the wall from layers of compacted earth. The tamped-earth process began with a simple wooden frame. Workers filled the frame with loose earth, which was then tamped into a compact layer 4 inches thick. The process was repeated layer upon layer, and the wall slowly rose 4 inches at a time. 

The Great Wall started as earth works thrown up for protection by different States. The individual sections weren't connected until the Qin dynasty (221-206 B.C.). Qin Shihuangdi, First Emperor of Qin began conscripting peasants, enemies, and anyone else who wasn't tied to the land to go to work on the wall. The tradition lasted for centuries. Each dynasty added to the height, breadth, length, and elaborated the design mostly through forced labor. 

Han Dynasty

The second Great Wall project was not as massive as the first, but it took on a new challenge: how to build a wall through the Gobi Desert. It also opened up China to the West as never before. Explore the opening of China. 

After the collapse of the Qin empire, China was one chaotic land. Even Qin Shi Huang's Great Wall started to fall apart, suffering from years of neglect. Again, China's northern frontiers were at the mercy of fierce outsiders known as the Xiongnu. In 206 B.C., a new dynasty, the Han, rose to power and began to move the empire in a new, more open direction. The Han restored much of China's classic literature, especially the works of Confucius. It also        established a strong but more humane central government, set up        the first public school system and, in a struggle that lasted nearly 70 years, crushed the Xiongnu menace once and for all. 

With this victory by Han Wu-Di, the greatest of the Han emperors, came a westward expansion into the wilderness of Central Asia. To protect that border Wu-Di began China's second great campaign of wall building. His engineers restored the crumbling Qin wall and extended it 300 more miles across the forbidding Gobi desert. 

With Central Asia under Han control, safe caravan routes -- the legendary Silk Roads -- were established, opening China to the commerce and culture of the Western world. Traders from Rome, Antioch, Baghdad and Alexandria trekked eastward to deal in jade, gold, spices, horses, precious gems and of course, silk. No matter what road they traveled, they could not reach their destination without passing through the Great Wall. 
Vibrant market towns soon flourished at these safe and busy gates, where traders from far-flung lands exchanged knowledge and ideas along with their goods. The world was changing, becoming smaller, and the Great Wall was playing a vital role. 

Secrets of the Han Wall

In the arid Gobi Desert, the poor quality of the sandy soil forced Han builders to resort to an ancient and painstaking method of wall construction. First, they laid a bed of red willow reeds and  twigs at the bottom of a wooden frame, then they filled the frame  with a mixture of water and fine gravel, which was tamped solid. When the mixture had thoroughly dried, the wooden frame was removed, leaving behind a solid slab  of tamped earth, strengthened by the willow reeds just as modern concrete is reinforced by steel rods. 

The Han also added beacon towers to the Wall, spaced 15 to 30 miles apart. Columns of smoke were used to warn defenders of an attack. One smoke column meant an outpost was being threatened by a force of fewer than 500 troops; two columns meant an attacking force of fewer than 3,000, and so on. The Han found the beacon system relayed messages faster than a rider on a horse. 

Ming Dynasty

Ming emperors not only rebuilt the crumbling wall, but they added many miles to it, creating a structure that could stretch from Miami to the North Pole. They also began closing their country to outsiders. 

The greatest of all wall builders were the Ming, whose astounding  accomplishments dwarfed what had been done earlier by the Qin  and the Han. The Ming not only built more wall than any other  dynasty, but theirs was also bigger, longer, more ornate and more  imposing. Theirs is the wall with which we're familiar.    But the Ming, who came to power in 1368, were much more than  master wall builders. They were also the architects of an age  during which China became a world economic power. Chinese  trade ships sailed as far as India, Japan, the Persian Gulf, and the  South Pacific, carrying endless payloads of porcelain, silk, spices, and a new drink that soon became the rage in Europe -- Chinese  tea. 

The Ming reign was a time of prosperity and intellectual vigor, but  it didn't last. Ming culture had always been susceptible to a deep  mistrust and condescending opinion of foreigners. In the mid-15th  century, Ming rulers abruptly curtailed foreign trade and began to  shun any kind of contact with the outside world. 

Secrets of the Ming Wall

The Ming, whose wall was built of a tamped earth interior encased in a facing of kiln-fired brick, pushed wall-building technologies to the limit. The Ming wall snakes acrobaticallyacross some of China's most forbidding terrain, rising in places at an angle of 70 degrees. Such dramatic engineering wouldn't have been possible without the Ming's advanced brick-making technology. At a time when European builders were still relying upon cumbersome cut stone, the Ming were using state-of-the-art kilns to mass produce bricks, which were as strong as modern-day masonry blocks. 

It was during the Ming dynasty (1368-1644) that the Wall took on its present form. The brick and granite work was enlarged and sophisticated designs were added. The watch towers were redesigned and modern canon were mounted in strategic areas. The Portuguese had found a ready market for guns and canon in China, one of the few items of trade that China didn't already have in abundance. The Ming Emperors, having overthrown the Hun dominance and expelled their Mongol rulers of the North devoted large portions of available material and manpower to making sure that they didn't return.

Since the 1600's parts of the Wall in some areas have been either dismantled to provide building materials in the area or have been buried by silt. We visited a restored section of the Wall at Badaling. When you stand on the Wall and look to the north you see the beginning of the great desert flatlands of the Hun. The view to the South is like a Chinese painting of layers of rolling hills covered by short brush and trees. The terrain is rough on both sides, and even today it is only accessible by a narrow road. 

Throughout the centuries, armies were garrisoned along the length of the Wall to provide early warning of invasion and a first line of defense. Great piles of straw and dung used to build signal fires have been found during excavations. There must have been small garrison towns spotted along the length. There weren't many farms or trade towns to provide ease, relaxation and food. The supply trails were over mountains along narrow paths. To bring supplies to the top, ropes were slung over posts set in the Chinese side of the wall and baskets were hauled up hand over hand. Supplies must have always been short and chancy, particularly in the winter. 

The Wall served well. Only when a dynasty had weakened from within were invaders from the north able to advance and conquer. Both the Mongols (Yuan Dynasty, 1271-1368) and the Manchurians (Qing Dynasty,1644-1911) were able take power, not because of weakness in the Wall but because of weakness in the government and the poverty of the people. They took advantage of rebellion from within and stepped into the void of power without extended wars. 

The Wall extends from peak to peak. The height of the mountains is used to command a greater view and for its advantage in defense. Always take the high ground, particularly if you are going to use bows and arrows and javelins. 

In about 220 B.C., under Qin Shin Huang, sections of fortifications which had been built earlier were joined together to form a united defence system against invasions from the north. Construction continued up to the Ming dynasty (1368-1644), when the Great Wall became the world's largest military structure. Its historic and strategic importance is matched only by its architectural value. 

Bibliography

Secrets of the Great Wall, Discovery Channel, Monday, July 5 at 9 p.m. ET.

UNESCO Web Site

NASA Web Site