– 168AD Claudius Ptolemaeus ( Greek : Κλαύδιος Πτολεμαίος Klaúdios Ptolemaîos ; 90 – 168), known in English as Ptolemy (pronounced /ˈtɒləmɪ/ ), was a Roman [1] mathematician , astronomer , geographer and astrologer . He lived in Egypt under the Roman Empire , and is believed to have been born