Across Europe, the Middle East and North Africa in the Medieval period, it was the authoritative text on astronomy, with its author becoming an almost mythical figure, called Ptolemy, King of Alexandria.
Overalt i Europa, Mellemøsten og Nordafrika var det i middelalderen den autoritative tekst om astronomi, og dens forfatter var en næsten mytisk figur, kaldet Ptolemæus, konge af Alexandria.