The Warring States period in Ancient Chinese history--which followed the period known as Spring and Autumn (770-476 B.C.) during the Chou (Zhou) Dynasty--ran from about 475-221 B.C. It was a period of violence and chaos during which the philosopher Sun-Tzu is said to have lived and culture to have flourished.
Seven States of China
There were about seven states of China during the Warring States period, including Yen, which was not one of the contending states, and 6 that were:
Two of these states, the Ch'in and Ch'u, came to dominate, and in 223, the Ch'in defeated the Ch'u, establishing the first unified Chinese state two years later. During the Spring and Autumn period, which preceded the Warring States, warfare was feudal and reliant on the war chariot. During the Warring Period, military campaigns were directed by the states who fitted out their soldiers with individual weapons.
Sources: Encyclopedia Britannica and The Oxford Companion to Military History.
During the Warring States Period, but elsewhere in the world, Alexander the Great conquered his enormous Hellenistic Greek empire, Rome came to dominate Italy, and Buddhism spread to China.