The first dynasty to unite most of China under a single government was the Zhou Dynasty. In 771 B.C. Zhou's king was killed by invading barbarians who were allied with rebel lords. The capital was moved eastward to Luoyang in present-day Henan Province. Because of this shift, historians divide the Zhou era into Western Zhou (1027-771 B.C.) and Eastern Zhou (770-221 B.C.). With the royal line broken, the power of the Zhou court gradually diminished; the fragmentation of the kingdom accelerated. Eastern Zhou divides into two subperiods. The first, from 770 to 476 B.C., is called the Spring and Autumn Period (), after a famous historical chronicle of the time; the second is known as the Warring States Period (475-221 B.C.).
The Eastern Zhou period is thought of as the 'shaping period' of Chinese culture. When the western Zhou started is uncertain but traditionally 1122 BC and 1027 BC are the dates given to us. The Zhou were a semi-nomadic clan from the north western fringe of the Chinese world. They replaced the Shang Dynasty. The capital was at Hao, near modern Xi'an. The government form there was a feudal monarchy. From a social standpoint the Western Zhou was quite similar to the Shang. The rulers were the nobles with family names and they practiced ancestor worship. Divination marked every important decision or event. Peasants were physically separated from other classes but were a key element. They carried out vital and supportive functions such as sewing and reaping.
The Zhou dynasty lasted longer than any other, from 1027 to 221 BC. It was the philosophers of this period who first enunciated the doctrine of the "mandate of heaven" (tianming or ), the notion that the ruler (the "son of heaven" or ) governed by divine right but that his dethronement would prove he had lost the mandate. The doctrine explained and justified the demise of the two earlier dynasties and at the same time, supported the legitimacy of present and future rulers.
The Eastern Zhou period is thought of as the 'shaping period' of Chinese culture. It is during this time when the uniqueness of China's recorded history begins, with the collections of documents, and historical romances coming to us. It was also during this time that the decline of the ancient forms of religion and the transformation into Confucianism and Daoism took place. From a social standpoint they created Legalism which is "a loose bundle of thinkers from different traditions rather than a proper school." This social organization was then adopted by other dynasties. It is also in this time that military thought and technology advanced.
The end of the Zhou period is in 221 BC when the first emperor of the Qin Dynasty unified the land on a new imperial basis.