Greek alphabet
There were some differences in the early Greek alphabet depending on what part of the Greek world it was used in. But over time, all Greeks started to use the same alphabet, especially after the Ionic alphabet of Miletus was officially adopted in Athens in 403 BC. A little later, the rest of Greece did the same, and by 350 BC, during the life of Alexander the Great, almost all Greeks were using the same twenty-four letter Greek alphabet.