古波斯語
As a written language, Old Persian is attested in royal Achaemenid inscriptions. The oldest known text written in Old Persian is from the Behistun Inscription, dating to the time of King Darius I (reigned 522–486 BC). Examples of Old Persian have been found in what is now Iran, Romania (Gherla), Armenia, Bahrain, Iraq, Turkey and Egypt. Old Persian is one of the oldest Indo-European languages which is attested in original texts.