The Han dynasty tried to fix the problems other dynasties had fallen to, such as government that was too centralized or fragmented. Instead, Han Gaozu allocated power to his family. This didn't work too well either, but the dynasty was still successful.
The Qin dynasty was very short, yet of great importance. The founder, Qin Shihuangdi, established centralized rule and divided China into provinces. He relied on his own loyal servants to rule the provinces rather than established nobility and disarmed regional military forces.
The Zhou dynasty established the Mandate of Heaven, a belief that a ruler's authority came from a higher power and could also be taken away if he acted unjustly. In addition to losing office, a ruler could sometimes have further consequences, like the destruction of his ancestral temple.
