Dorotheus of Sidon (Greek: Δωρόθεος Σιδώνιος, c. 75 CE - ?? CE) was a 1st-century Hellenistic astrologer who wrote a didactic poem on horoscopic astrology known in Greek as the Pentateuch (five books). The Pentateuch, which was a textbook on Hellenistic astrology, has come down to us mainly from an Arabic translation dating from around 800 AD carried out by Omar Tiberiades (itself a translation of a Middle Persian translation from the original Greek). The text, fragmentary at times, is therefore not entirely reliable, and is further corrupted by interpolations by the later Persian translators. Nevertheless, it remains one of our best sources for the practice of Hellenistic astrology, and it was a work of great influence on later Christian, Persian, Arab and medieval astrologers. The late 1