The history of the administrative divisions of the Imperial China is quite complex. Across history, what is called 'China' has taken many shapes, and many political organizations. For various reasons, both the borders and names of political divisions have changed—sometimes to follow topography, sometimes to weaken former states by dividing them, and sometimes to realize a philosophical or historical ideal. For recent times, the number of recorded tiny changes is quite large; by contrast, the lack of clear, trustworthy data for ancient times forces historians and geographers to draw approximate borders for respective divisions. But thanks to imperial records and geographic descriptions, political divisions may often be redrawn with some precision. Natural changes, such as changes in a river's course (known for the Huang He, but also occurring for others), or loss of data, still make this issue difficult for ancient times.
Before the establishment of the Qin Dynasty, China was ruled by a network of kings, nobles, and tribes. There was no unified system of administrative divisions. According to ancient texts, China in the Xia and Zhou dynasties consisted of nine zhou, but various texts differ as to the names and even functions of these zhous.
During the Zhou dynasty, the nation was nominally controlled by the "Son of Heaven". In reality, however, the country was divided into competing states, each with a hereditary head, variously styled "prince", "duke", or "king". The rivalry of these groups culminated in the Warring States period, which ended with the victory of Qin.
After the Kingdom of Qin managed to subdue the rest of China in 221 BC, the First Emperor divided his realm into relatively small commanderies, which were divided into still smaller counties. Repudiating the fiefs of the Zhou, both levels were centrally and tightly controlled as part of a meritocratic system. There was also a separately-administered capital district known as the Neishi.