Why this is not another book on Celtic astrology. To our knowledge, there is no other book on the topic of ancient Celtic astrology. It is an in-depth research on what was, or must have been, the speculations and teachings of the ancient Druids on the subjects of cosmology, astronomy and astrology. Our present understanding of what was Celtic astrology is based mainly on the speculations of modern authors such as Robert Graves, et alia, and thus suffers many misconceptions. The critical review of eminent scholars such as the Vedantist Dr. David Frawley, the Celticist Joseph Monard, provided a plausible working model for ancient druidical astrology. To my knowledge, no other book has thoroughly expounded this difficult subject.