Geography (Ptolemy)

The Geography (Ancient Greek: Γεωγραφικὴ Ὑφήγησις, Geōgraphikḕ Hyphḗgēsis, lit. "Geographical Guidance"), also known by its Latin names as the Geographia and the Cosmographia, is a gazetteer, an atlas, and a treatise on cartography, compiling the geographical knowledge of the 2nd-century Roman Empire. Originally written by Claudius Ptolemy in Greek at Alexandria around 150 AD, the work was a revision of a now-lost atlas by Marinus of Tyre using additional Roman and Persian gazetteers and new principles.

Its translation into Arabic by al-Khwarismi in the 9th century was highly influential on the geographical knowledge and cartographic traditions of the Islamic world. Alongside the works of Islamic scholars—and the commentary containing revised and more accurate data by Alfraganus—Ptolemy's work was subsequently highly influential on Medieval and Renaissance Europe.