The Astrological Chart of the Coronation of King Sebastião of Portugal

Abstract

The presence of Jewish astrologers in the Portuguese court of the fourteenth and fifteenth centuries is frequently mentioned in the chronicles of the kings. In 1496, King Manuel I forced the Jews to choose between conversion to Catholicism and expulsion. Those noblemen had to leave the court, and many of them also left the kingdom. In 1529, King João III created the position of Royal Cosmographer, the mathematician Pedro Nunes being the first to occupy the position. Pedro Nunes was apparently a severe opponent of astrology except for one episode: a few days before the coronation of King Sebastião in 1568, Pedro Nunes allegedly suggested to the Queen-regent, that she should postpone the ceremony, claiming astrological reasons. Historians relate this episode to a similar one, more than a century earlier, featuring the coronation of King Duarte (Edward) in 1433, and some believe that the alleged incident with King Sebastião may be just one more legend about this charismatic king. In this text we discuss the possibility that Pedro Nunes had actually made and examined the astrological chart for the moment of the coronation of King Sebastião.