The Mandate of Heaven (天命) was a principle used to justify the power of the emperor of China, as well as explaining suitability for the office. According to this belief, heaven bestows its mandate to a just ruler, the Son of Heaven. The Mandate of Heaven depends on the virtue of the emperor; if he does not fulfill his obligations as emperor, then he loses the Mandate and thus the right to be emperor. The Mandate of Heaven would then transfer to whoever would rule best. The fact that a ruler was overthrown was taken by itself as an indication that the ruler had lost the Mandate of Heaven. In addition, it was also common belief that natural disasters such as famine and flood were other signs of heaven’s displeasure with the current ruler, so there would often be revolts following major environmental events as citizens saw these as signs of heaven's displeasure.
The Mandate of Heaven does not require that a legitimate ruler be of noble birth, and dynasties were often founded by people of common birth (such as the Han dynasty and Ming dynasty). The Mandate of Heaven had no time limitations, depending instead on the just and able performance of the ruler and his heirs. Throughout the history of China, times of poverty and natural disasters were often taken as signs that heaven considered the incumbent ruler unjust and thus in need of replacement.
The concept of the Mandate of Heaven was first used to support the rule of the kings of the Zhou dynasty(1046-256 BCE), and their overthrow of the earlier Shang dynasty(1600-1046 BCE). It was used throughout the history of China to support the rule of the emperors of China, including non-Han ethnic monarchs such as the Qing dynasty. This concept was also applied to nearby countries like Korea and Vietnam
