The Mandate of Heaven is a Chinese doctrine that has been in use since the Zhou dynasty of China. Put simply, it was a form of justification to the 'divine' rule of the Emperors, as well as any subsequent overthrows of power. The Mandate of Heaven was like divine favor, and when a rebellion successfully occurs, it is considered a sign that this favor has left the rulers of the time, and was therefore inherited by those who overthrew them. This means that when the previous ruler is overthrown, the newly established ruler should be considered completely legitimate from a divine perspective.