Ptolemy's ancient all-in-one astrology manual, Tetrabiblos because it has "four books" or sections, . Astrologers have long called it "the bible of astrology." Claudius Ptolemy of Egypt wrote the book late in his life, which was about 150 years after Christ, compiling and organizing what his ancient world knew about predictive astrology--an art and science that might have been lost to us except that handwritten copies of Tetrabiblos survived in Greek, Arabic, and Latin, because even when astrology was forbidden there were always those who against the rules could appreciate it.
Ptolemy was an astronomer and astrologer when those disciplines were one. From his many other books we know he was above all a scientist and mathematician who believed in logic and order, and he saw--he proved--the mathematical basis of planetary motion

Tetrabiblos combines science and art to explain how stars and planets yield meaning. This book laid the foundation for Western astrology as it is practiced today. Scholars who can read the original Greek admire Ptolemy as a mathematician and scientist, yet agree that he was not a good writer. In fact Tetrabiblos was such difficult reading that by the ninth century C.E. another writer had paraphrased the book to make it more readable. Preserved in an Arabic manuscript, this "Paraphrase of Proclus" is the oldest surviving version of Tetrabiblos. Compared with the full text, it cuts corners and contains inaccuracies.

This new translation is the full text, adapted from the two most recent English translations, published in 1822 and 1940.