Renaissance astrology is often considered to have been some arcane stab at witchcraft, a joke that was practiced by snake oil salesman and gypsies as they traveled from town to town ripping rubes off by the bucket loads using fakirs and charlatans planted in the crowds that were full of gullible peasantry, but in reality, astrology, the science that it is known as today, much like most modern science, got its legitimate start as renaissance astrology. Renaissance astrology was taken seriously by William Lilly and astrologers like Morin de Villenfraiche, both of whom furthered the cause that astrology was not just an occult ritual, but in fact a legitimate science based on lunar placement.

William Lilly practiced a different form of renaissance astrology known as horary astrology. Horary astrology uses the same basic principles of utilizing lunar placement and planetary placement to predict horoscopes, but it builds its charts based on when the question was posed, not when the person was born. In other words, the horoscope is built around the exact time that a person asked a question that they wanted an answer to. The horoscope chart would have nothing to do with the placement of the moon, planets, or sun when the person was born. William Lilly was so accurate and successful with his horary astrology that he was accused and tried before Parliament for setting the Great Fire of London because he accurately predicted the event fourteen years before it occurred. He was acquitted as there was no basis for the accusations, and this added to the astrology icons great legend.

William Lilly practiced renaissance astrology or horary astrology until his death in sixteen eighty-one, dabbling mainly in occultism and the practice of medicine late in his life. William Lilly wrote Christian Astrology in sixteen forty-seven. Christian Astrology was a large work that chronicled his views, beliefs, and practices. The book is printed in three volumes to this day and it has never gone out of print. William Lilly's methods and ideals are still practiced to this day by horary astrologers. Lilly's methods were so accurate that he is largely credited with transforming the image of the astrologer from that of a seedy seer or practicing witch to that of a scientist.

William Lilly's works were actually revered by some members of Parliament at the time. He was so confident in his methods that he printed almanacs of predictions, which of course led to the aforementioned arrest and trial pertaining to the great fire.

William Lilly guided renaissance astrology through the dark ages, out of the circus or carnival, and into the light of day where it was to be taken seriously by mainstream society. Were it not for William Lilly, astrology may still be considered a side show or freak act to this day. William Lilly is considered to this day to be one of the greatest figures in the colorful history of astrology. He is perhaps the greatest, if not most accurate astrologer of all time.