The four centuries of the Han dynasties from 206 BC to AD 220 witnessed major developments in the ideas of sovereignty. Michael Loewe traces these changes along with some of their religious aspects, including the techniques used by emperors and others to forecast the future or to divine the present. Both mythology and the tradition of learning affected the growth of the imperial ideal that, despite its failings, was of major importance both for the Han and China"s subsequent dynasties.