For thousands of years, it was thought that Heaven bestowed the right to rule the Earth only on those who are virtuous and capable. Natural disasters are ominous signs of heaven's displeasure with the ruling dynasty and this leads to unrest among the populace. A new leader, whoever it may be, is needed to restore order. The Mandate of Heaven does not choose based on status or race, as peasants and foreigners have become emperors of the Middle Kingdom in the past.