As one of the First Civilizations, China had a tradition of state building that historians have traced back to around 2000 B.C.E. or before. When the Zhou dynasty took power in 1122 B.C.E., the notion of the Mandate of Heaven had taken root, as had the idea that the normal and appropriate condition of China was one of political unity. By the eighth century B.C.E., the authority of the Zhou dynasty and its royal court had substantially weakened, and by 500 B.C.E. any unity that China had earlier enjoyed was long gone. What followed was a period (403–221 B.C.E.) of chaos, growing violence, and disharmony that became known as the “age of warring states.” During these dreadful centuries of disorder and turmoil, a number of Chinese thinkers began to consider how order might be restored, how the apparent tranquility of an earlier time could be realized again. From their reflections emerged classical cultural traditions of Chinese civilization.