Astrology has been used as a weapon by powerful people since ancient times. So powerful, in fact, that many Roman emperors throughout history have banned astrology at different periods in order to keep the knowledge out of common people’s – and their enemies’ – hands.
An astrologer predicted Augusts’ rise to power. Domitian was an emperor who studied the natal charts of his enemies to ensure that they didn’t have the potential to overthrow him. And if they did, he had them killed. Not everyone used astrology for evil purposes, however: the emperor Hadrian used it to choose a successor.
Because of the negative uses of astrology, a person’s natal chart was treated as something to be guarded. Many astrologers would predict the death of emperors, and emperors had astrologers to advise them. Wouldn’t a really cool premise for a fantasy book be the banishment of astrology, only to be used secretly in the future later on as a weapon against a tyrannical empire? Oh, wait – I wrote that book!