Astrology is the study of how planetary positions affect human behavior. It originated in ancient Egypt where astrologers believed the patterns of the stars influenced human lives and seasons. After the Norman conquest, astrological knowledge spread to England through Jewish and Arabic scholars. A famous English astrologer, Adelard, translated several Arabic astrological works and influenced figures like King Henry II. In the medieval period, astrology was used for medical diagnoses and cures based on beliefs about the influence of signs like the Moon and Sagittarius on personality traits and health.