Complex sentence: Astrological practices of divination and planetary interpretation have been used for millennia to answer political questions, but only with the gradual emergence of horoscopic astrology, from the sixth century BC, did astrology develop into the two distinct branches of mundane astrology and natal astrology.
Split into simpler sentences: Astrological practices of divination and planetary interpretation have been used for millennia to answer political questions. It was, however, only with the gradual emergence of horoscopic astrology from the sixth century B.C. that astrology developed into two distinct branches, mundane astrology and natal astrology.