The Great Wall of China
It was the state Chu who first builf the wall.
To defend off the invasions from northern invaders Emperor Qin Shi Huang had all the walls joined up Thus, the Great Wall came into being..
The primary purpose was always to protect the Chinese Empire from the Mongolians and other invaders. Source: IndiaFacts
Millions of the people together constructed the Great Wall. The labor force included workers, soldiers, forcibly recruited peasants, slaves, convicts and war prisoners.
Why was it built?
The Great Wall of China was built to protect China from its enemies and invaders from the North, mostly the Mongols.
If you did not know, China is not the only country in history that built wall along its boundary. Other countries Athens, the Roman Empire, Denmark and Korea all did so at certain time in the past.
Proto Korean Peoples Xian-Wun Chuan-Rong DiThou The Great Wall of China, originally built in the seventh century B.C, worked as a defence for the feudal states of the Zhou Dynasty Dynasty Shu Wu Proto- Thai Yue Peoples PopleMalavs
The Great Wall was the greatest military defence project in the history, and it was also the guarantee of the peace and stability of ancient society and agriculture.