Because an equivalent of "ērānšahr" does not appear in Old Iranian (where it would have been "*aryānām xšaθra-" or in Old Persian "*- xšaça-", "rule, reign, sovereignty"), the term is presumed to have been a Sasanian-era development. In the Greek portion of Shapur's trilingual inscription the word "šahr" "kingdom" appears as "ethnous (genitive of "ethnos")" "nation". For speakers of Greek, the idea of an Iranian "ethnos" was not new: The mid-5th-century BCE Herodotus (7.62) mentions that the Medes once called themselves "Arioi". The 1st century BCE Strabo cites the 3rd-century BCE Eratosthenes for having noted a relationship between the various Iranian peoples and their languages: "beyond the Indus [... Ariana is extended so as to include some part of Persia, Media, and the north of Bactria and Sogdiana; for these nations speak nearly the same language." ("Geography", 15.2.1-15.2.8). Damascius ("Dubitationes et solutiones in Platonis Parmenidem", 125ff) quotes the mid-4th-century BCE Eudemus of Rhodes for "the Magi and all those of Iranian ("áreion") lineage". The 1st-century BCE Diodorus Siculus (1.94.2) describes Zoroaster as one of the "Arianoi".