The period of Spring and Autumn (772 BC ~ 476 BC) and the Warring States (475 BC ~ 221 BC)
The Warring States is a period in Chinese history. It lasted from 475 BC to 221 BC. Before this period was the Zhou Dynasty. In the later part of the Zhou Dynasty, the king began to lose his power as officials and royal family members started the struggle for land and power. War broke out. Following the Zhou Dynasty is the Spring and Autumn Period when there were many states in China. They did not stand united. The Warring States Period comes next. During this period, there were only seven states in the territory of China. After so many years of fighting, peace was still not acquired. The seven states were Qi, Chu, Yan, Han, Zhao, Wei and Qin. In these states, Qin was the most powerful while Chuís territory was the largest. It was during this period that the Great Wall was first built.
The purpose of building the walls by various states was not merely to protect themselves from the attacks of the tribes to the North of China. The aim was also to protect themselves from invasion of the other states.
Warring States Qin Dynasty Han Dynasty N. & S. Dynasties
Tang Dynasty Song Dynasty Yuan Dynasty Ming Dynasty Qing Dynasty