Claudius Ptolemaeus (Greek: Κλαύδιος Πτολεμαῖος; ca. 100 – ca. 178), known in English as Ptolemy, was an ancient geographer, astrologer, and astronomer who probably lived and worked in Alexandria, off the coast of Egypt.
Ptolemy was the author of several scientific treatises, two of which have been of continuing importance to later Islamic and European science. One is the astronomical treatise that is now known as the Almagest (in Greek Η μεγάλη Σύνταξις, "The Great Treat ...
Ptolemy's other main work is his Geographia. This too is a compilation of what was known about the world's geography in the Roman Empire during his time. He relied mainly on the work of an earlier geographer, Marinos of Tyre, and on gazetteers of the Roman and ancient Persian empire, but most of his sources beyond the perimeter of the Empire were unreliable.
The first part of the Geographia is a discussion of the data and of the methods he used. Like with the model of the solar system in the Almagest, Ptolemy put ...
Ptolemy's treatise on astrology, the Tetrabiblos, was the most popular astrological work of antiquity and also enjoyed great influence in the Islamic world and the medieval Latin West. The Tetrabiblos is an extensive and continually reprinted treatise on the ancient principles of astrology in four books (Greek tetra means "four", biblos is "book"). That it did not quite attain the unrivalled status of the Syntaxis was perhaps because it did not cover some popular areas of the subject, particularly horary as ...
Ptolemy's treatise on astrology, the Tetrabiblos, was the most popular astrological work of antiquity and also enjoyed great influence in the Islamic world and the medieval Latin West. The Tetrabiblos is an extensive and continually reprinted treatise on the ancient priciples of astrology in four books (Greek tetra means "four", biblos is "book"). That it did not quite attain the unrivalled status of the Syntaxis was perhaps because it did not cover some popular areas of the subject, particularly horary ast ...