Feudalism allowed large territories to be governed in the absence of a central government. Each lord or vassal raised an army to defend his fief and to serve the king as needed. One drawback to this system was that the nobles were very powerful because they controlled the armies.
Because they had more support from the beginning. And they had slaves which supported the factories in the North. The North relied heavily on them.
The Zhou created the Mandate of Heaven: the idea that there could be only one legitimate ruler of China at a time, and that this ruler had the blessing of the gods. They used this Mandate to justify their overthrow of the Shang, and their subsequent rule
