The Great Wall of China, also known as the "Chinese Wall," is a series of fortifications made of stone, brick, tamped earth, wood, ..

 The Great Wall of China, also known as the "Chinese Wall," is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China to protect the Chinese states and empires against the raids and invasions of the various nomadic groups of the Eurasian Steppe. The wall is the longest in the world, stretching over 13,000 miles.

The history of the Great Wall of China can be traced back to the 7th century BCE, during the rule of the state of Qi in the Spring and Autumn period. The Qi built walls to defend against raids by the neighboring state of Chu. The walls were not a single continuous wall but were made of separate sections built by different states.

During the Warring States period (475-221 ), the states of Qi, Chu, Yan, and Zhao all built walls along their borders to defend against invasions. The State of Qi built the longest walls, stretching over 1,000 miles, but they were not a single continuous wall.

The first emperor of China, Qin Shi Huang, who ruled from 221 to 210 BCE, ordered the joining of the separate walls built by the Warring States to create a single continuous wall to defend against invasions by the Xiongnu people from the north. The work was completed in a remarkable 20 years, but most of the walls were made of earth and wood and have long since disappeared.

In the Ming dynasty (1368-1644), the Great Wall was rebuilt and extended, with the wall being constructed mainly of brick and stone. The wall was also outfitted with watchtowers, barracks, and artillery platforms. The Ming Great Wall is the one that is most recognizable today and is the best-preserved section of the Great Wall.

The Great Wall has had a complex history and is a symbol of Chinese civilization. It is one of the most extensive building projects ever completed and is a UNESCO World Heritage site. The Great Wall is not just a military fortification, but also a symbol of Chinese civilization and a source of Chinese pride. Despite its historical significance, it was not always successful in keeping out invaders, but it remains an iconic architectural and engineering achievement.