The Zhou Dynasty is traditionally divided into two periods: Western Zhou (11th century BC-771BC) and Eastern Zhou (770BC-221BC). And the Eastern Zhou has two periods: the Spring and Autumn Period (770BC-476BC) and the Warring States Period (476BC-221BC).
Spanning 2,700 years of Chinese history, ranging from the Spring and Autumn Period and the Warring States Period to the Ming Dynasty (1368-1644), over twenty states and dynasties were involved in the building of the Great Wall. The creation of the wall was initiated during the Spring and Autumn Period and the Warring States Period to prevent the invasion by other states of China and outer tribes.