The Great
Wall of China is the largest manmade structure in the world and consists of a
series of stone and earthen fortifications in northern China, built to protect
the borders of the Chinese Empire against various invasions. Several walls have
been since built and maintained from the 5th century BC through the
16th century. One of the most famous is the wall built between
220–206 BC by the first Emperor of China, Qin Shi Huang. Little of that wall
remains; the majority of the existing wall was built during the Ming Dynasty.
History
The
Chinese were already familiar with the techniques of wall-building by the time
of the Spring and Autumn Period, which began around the 8th century
BC. Built to withstand the attack of small arms such as swords and spears,
these walls were made mostly by stamping earth and gravel between board frames.
Qin Shi Huang conquered all opposing states and unified China in 221 BC,
establishing the Qin Dynasty. He ordered the destruction of the wall sections
that divided his empire along the former state borders and ordered the
construction of a new wall to fortify the empire.
The
Dynasties that followed such as Han and Sui expanded the wall but the Tang and
Song did not build any walls. During the Ming Dynasty to prevent the Manchurian
and the Mongol raids the wall was repaired and expanded, the fortifications
being stronger with the use of bricks and stones. The wall withstood many a
raid but in 1644 the Manchus finally crossed the Great Wall and seized Beijing
and defeated the remaining Ming resistance establishing the Qing Dynasty rule
over entire China.
General Information
The most comprehensive archaeological
survey, using advanced technologies, has concluded that all the walls measure
8,851.8 km (5,500.3 miles). In Chinese the wall is called
"Wan-Li Qang-Qeng" which means 10,000-Li Long Wall (which is around
5,000 km). Its thickness ranged from about 4.5 to
9 meters (15 to 30 feet) and was up to 7.5 meters (25 feet) tall. It stretches from Shanhaiguan in the
east, to Lop Lake in the west, along an arc that roughly delineates the southern
edge of Inner Mongolia. Communication between the army units
along the length of the Great Wall, including the ability to call
reinforcements and warn garrisons of enemy movements, was of high importance.
Signal towers were built upon hill tops or other high points along the wall for
their visibility. It is claimed that the Great Wall can
be seen from space as well as from the moon. But astronauts have dismissed this
although from a low earth orbit under perfect conditions it may be visible to
the naked eye.
