Dorotheus of Sidon, who appears to have lived in Alexandria, flourished in the first century AD. He wrote his Pentateuch (five books) on astrology in Greek, in verse. This translation, from 1976 by David Pingree, is from a fourth century Pahlavi (Persian) source. The first book is on the judgement of nativities. Book two concerns marriage and children. Book three is on the length of life. Book four is on the transfer of years, i.e., forecasting. Book five is on interrogations, i.e., electional astrology. In this book are the earliest known astrological charts. Dorotheus bases much of his interpretative methods on the triplicity rulers, by day and by night. All fire signs have the same rulers. All earth signs have their rulers, as do air and water signs. He uses Egyptian terms. He, like the Greeks of his day, also uses the Dodecatemoria, which are the twelfths of a sign. And many, many lots, all defined. For the first time in this edition: Pingree's Preface newly translated. An appendix with charts in modern format. A complete table of terms and triplicity rulers. A table to calculate Dodecatemoria. Newly reset to match Pingree's original 1976 edition. Written a century before Ptolemy, here is the mainstream of Greek astrology. It will handsomely repay study.