The Mandate of Heaven does not require a legitimate ruler to be of noble birth, and dynasties such as the Han and Ming dynasties were founded by men of common origins. The Mandate of Heaven had no time limitations, depending instead on the just and able performance of the rulers and their heirs. The concept is in some ways similar to the European concept of the divine right of kings; however, unlike the European concept, it does not confer an unconditional right to rule. The concept of Mandate of Heaven also included the right of rebellion against an unjust ruler. Chinese historians interpreted a successful revolt as evidence that Heaven had withdrawn its mandate from the ruler. Throughout Chinese history, times of poverty and natural disasters were often taken as signs that heaven considered the current ruler unjust and in need of replacement. The Mandate of Heaven was often invoked by philosophers and scholars in China as a way to curtail the abuse of power by the ruler. 