How Astrology Became a Capital Crime: Royal Assassination Fears

During the post-medieval period in Europe, horoscopes were viewed as not just entertainment but also as scientifically valid and divinely inspired. Their ability to predict events became a tool for political manipulation, with the act of forecasting a monarch's death classified as treason. This concern led to legal actions, starting with a 1581 law under Elizabeth I that made it a capital crime to cast horoscopes predicting her demise. Her successor, James I, escalated the persecution of astrologers linked to the royal family. Earlier, in 11 CE, Emperor Augustus prohibited such forecasts, while Emperor Tiberius used horoscopes to justify executing rivals. In Italy, predictions regarding papal deaths led to economic turmoil, prompting Pope Sixtus V to declare judicial astrology heretical. An astrologer’s accurate prediction of Pope Urban VIII's death in 1631 marked a significant moment. The decline of astrology as a credible science was hastened by Johannes Kepler, whose Rudolphine Tables demonstrated elliptical orbits and introduced rational mathematics, aiding the Enlightenment. In 1682, King Louis XIV of France ceased the prosecution of astrologers, relegating them to the status of frauds with lesser penalties. Ultimately, the combination of royal apprehension, Kepler's discoveries, and the Vatican's Inquisition led to astrology's fall from scientific legitimacy.