The history of China is extremely complex in that it is spread over several millennia, that it is composed of several great periods during which it oscillates between a bursting in many small kingdoms and military conquests of vast territories regrouping disparate peoples. The territory of what we know of the current Chinese nation has fluctuated enormously over the centuries, but it has always been formed in an approximately homogeneous set north of the Himalayan mountains, along the Pacific coast. His most frequent enemies were the Manchu neighbors (who were at the origin of the last imperial dynasty), the Tartars, and the Mongols, also at the origin of an important dynasty, the Yuan.
Each dynasty is made up of several emperors, the remaining power in the family from generation to generation. From 1912 China became a republic but its history does not stabilize so far as still the country is divided into two separate nations, the People's Republic of China and Taiwan.
There are three main periods in the history of China: The pre-imperial period (-1767 to -221), the imperial period (-221 to 1912) and the contemporary period (1912 to the present). Since the imperial period is very long, it has been divided into several parts that correspond to historically coherent notions.
It would be the oldest known Chinese dynasty. Occupying a relatively small territory in present-day North China, it would have ruled before the sixteenth century BC. It is considered to be at the origin of the whole history of China, but it could well be only an imaginary dynasty destined to anchor the continuation in a historically vague context.
From -771 the Zhou fall back on the eastern part, then begin the reign of the Zhou of the East.
The fall of the Han causes the division of their territories into three parts: The kingdom of Wei, the kingdom of Wu and the kingdom of Shu. They were all three conquered by the Jin dynasty which was created later. These three kingdoms therefore lived in parallel and ended at ages a little off.
At the fall of the western Jin the territory of China is split in two, a northern part in which takes place what we call today the "Sixteen Kingdoms", and a southern part where we find the eastern Jin.