These high walls laid the foundation for the present Great Wall. In Chinese history, this is the largest project carried out in 3 dynasties that brought the climax of the development of the Great Wall. Large-scale construction of the Great Wall was concentrated in the Qin, Han and Ming dynasties. U wanna hear the story? Let me tell you~

The sections of the wall began to be called the Great Wall in the time of Qin Shihuang, the First Emperor of the Qin Dynasty.

It was in 221 B.C., when Qin conquered the other states and unified China, Emperor Qin Shihuang, who paid more attention to military affairs, ordered the connection of these individual walls and further extensions to ward off harassment by the Huns-an ancient nationality in northern China, and for the use of further defensive projects. Then, he sent Meng Tian, a military general, with 300 and thousand soldiers and 1 million civilian[1 fifth of China's population at that time] up to north to build up the Great Wall. When the linking work finished 10 years later, the total length of the Great Wall was 7,000 kilometers long over 5,000 kms long. This was the first 'climax of the development of the Great Wall

During the Han Dynasty, in order to ward off the Huns as well as to protect the newly opened Silk Road, they not only maintained and utilized the Qin Great Wall but also built an Outer Great Wall. They also had the Great Wall extended westwards to the Lop Nur Lake in today's Xinjiang. The Han Dynasty period became the second climax of construction on the Great Wall.