Great Wall of China

The **Great Wall of China** (, literally "ten thousand _li_ long wall") is a series of fortifications in China. Chinese emperors and dynasties built the wall (and joined together existing walls) to protect the north of their empire from enemy attacks. In total, the wall stretches .

The first walls were built in the 7th century BCE. Later, during the Qin dynasty (which ruled China from 221 BCE to 206 BCE), these walls were connected. Later dynasties continued construction on the wall system. Between the 3rd century BCE to the 17th century CE, it was under construction continuously.

The Ming dynasty (which ruled from 1368 CE to 1644 CE) built the best-known sections, which stretch between 4,000 and 5,500 kilometers (2,500 and 3,400 miles).

The Great Wall is one of the largest man-made projects in the world. It is a UNESCO World Heritage Site.

### Beginnings

Great Wall of Qi was started in 685 BC. The state of Qi made a fortified wall for protection against the Southern states Ju and Lu and later from the kingdom Chu.

The state of Yan built walls during the rule of King Zhao of Yan (311–279 BC).

The state of Zhao built walls during 325–299 BC, during the rule of king Wuling of Zhao.

### Qin dynasty

The First Emperor of China, Qin Shi Huang also called Shi Huangdi, started the Qin Dynasty. The Xiongnu tribes in the north of China were his enemies. The land in some parts of China is easy to cross, so Qin Shi Huang started building the Great Wall to make it more difficult for the Xiongnu to invade China.

The most famous part of the Great Wall was built between 226 and 200 BC by the first Emperor of China, Qin Shi Huang (Qin Pronounced as Chin), during the Qin Dynasty.

Walls on the periphery of the Northern states Yan, Zhao, and Qin became linked together, because all those states came under the rule of emperor Qin Shi Huang during his rule (221–206 BC).

By 212 BC, the wall went from Gansu to the coast of South Manchuria.

### Expansion

Other dynasties in China continued to build and lengthen the Great Wall. The Han, Sui, Northern and Jin Dynasties all repaired, rebuilt or expanded it. Their goal was to protect China from Mongol invasions from the north.

During the Ming Dynasty (1368 CE - 1644 CE), Chinese leaders built between 4,000 and 5,500 kilometers of new wall (2,500 and 3,400 miles). On average, these walls were 21.3 feet (6.5 metres) wide at the base, 19 feet (5.8 metres) wide at the top, and 7 to 8 meters (23 to 26 feet) tall. They are made of mortar, rocks, adobe bricks, and dirt.

## Nine Garrisons of the Ming dynasty

During the Ming dynasty, Chinese rulers built the Nine Garrisons (also called the Nine Defense Areas). These were meant to protect the northern border and the Great Wall. It grew to have 11 garrison<nowiki/>s:

- Gansu Garrison; Its area of responsibility was from Lanzhou on the Yellow River, to the Jiayu Pass (map). Its headquarters were in present-day Zhangye city (map); .
- Guyuan Garrison, also known as the Shaanxi Garrison, was headquartered in present-day  Guyuan, Ningxia.
- Ningxia Garrison, was headquartered in present-day  Yinchuan, a city located on the Yellow River.
- Yansui Garrison, area of responsibility: from Yanchi (map) in Ningxia, to Fugu on the Yellow River. Headquarters were in present-day Yulin.

- Taiyuan Garrison, also known as the Shanxi Garrison; Area of responsibility, from Hequ (map) on the Yellow River, facing east past Yanmenguan towards the Taihang Mountains on the border of Hebei, to the Zhenbao Wall. Control of the garrison happened from  Pianguan.
- Datong Garrison, was headquartered in present-day  Datong,
- Xuanfu Garrison; Area of responsibility, from Huai'an (map), northeast of Datong, to Juyongguan (map), north of Beijing. Headquarters near present-day Xuanhua

- Zhenbao Garrison, was headquartered in present-day  Baoding,
- Changping Garrison, , was headquartered in present-day Changping,
- Jizhou Garrison (薊州鎮), also known as Ji, was headquartered in present-day Santunying, northwest of Qianxi.
- Liaodong Garrison, was headquartered in present-day Liaoyang.

## Construction and rebuilding of the Great Wall

Builders used materials that were nearby. Some parts of the wall were made of mud, straw, and twigs. Thousands of workers died from giant falling stones, exhaustion, disease, animal attacks, and starvation. The idea that workers died and were buried in and under the Great Wall is a myth.

## Visibility from space

A astronaut named William Pogue was able to see the wall from a Low Earth Orbit (300–530 km above Earth), but only with binoculars and a lot of practice. Another astronaut, Neil Armstrong, said that on the Moon, it was very clear that the wall was not visible. The Great Wall has shown up in some photos taken from space, but scientists are sure it is not possible for astronauts to see the wall without binoculars.

## Sources

- Di Cosmo, Nicola (1999). "13. The Northern Frontier in pre-Imperial China". In Loewe, Michael; Shaughnessy, Edward (editors). The Cambridge History of Ancient China. Cambridge: Cambridge University Press. ISBN 978-0-521-47030-8.