The sections of the wall began to be called the Great Wall during the reign of Qin Shihuang (259-210 BC), the First Emperor of the Qin Dynasty. In 221 BC, Qin Shihuang defeated the other six kingdoms and unified China. Since the six states were all conquered by him, the first united feudal empire in Chinese history came into being. He established the first centralized feudal country and gave himself the title- the First Emperor of the Qjn Dynasty, Emperor Qjn Shi Huang (Shi means start). In order to consolidate the unity of the country, he not only made use of the common law, the standardized system of currency, weight and measures but also paid great attention to military affairs. He decided to link up the separate sections of high walls built by different kingdoms into the Great Wall. Especially the high walls in the northern part of China built by State Qin, Zhao and Yan, in order to ward off harassment by the Huns (an ancient nationality in northern China) and for the use of further defensive projects. Many sections of the Wall were linked up, expanded, and finally it was extended into the Great Wall.

The linking work took 10 years to finish at the end of the Qin Dynasty in 206 BC. About 300, 000 soldiers and one million people, almost one fifth of China’s population at that time, were involved in the project. When it was finished, the total length of the Great Wall was over 5,000 kilometers long; so it was called “Wan Li Chang Cheng” in Chinese, which means Ten Thousand Li Long Wall. (Li is the Chinese unit of measurement which is 500 meters). The Qin Great Wall started from Lintao, Gansu Province in the west and ended in Liaodong, Liaoning Province in the east.