Warring States Period
The Zhou Dynasty came to an end during the Warring States period in 256 BCE, when the army of the state of Qin captured the city of Chengzhou and the last Zhou ruler, King Nan, was killed. The real power of Zhou was so small, that the end of the dynasty was hardly noted. The Zhou state was thus absorbed by the state of Qin. The supremacy of the states of Qin, Qi and Chu was so great that it seemed for a time that China would be divided in three, one section for each state. However, chaos and war prevailed and the battles continued until eventually the state of Qin conquered the other states and unified China once more in 221 BCE, the beginning of the Qin Dynasty (221-206 BCE).