Parthian moγ and Middle Persian moγ/mow in Light of Earlier Eastern and Western Iranian Sources

The present article analyses the historical importance assumed by Parthian and Middle Persian moγ/mow (and related words) in the framework of the religious and administrative language of Late Antiquity despite its seemingly absolute absence in the Avestan Sprachgut. Although moγ should be reasonably considered as a word of (prominent) Western Iranian derivation, i.e. from Median and Old Persian magu-, the progressive phonetic evolution toward a spelling, such as that of early Parthian and Middle Persian *moγ(u)- created a fitting resonance with a rare Avestan word (in its turn probably nonexistent in the older strata of the language, if not even a Western loanword itself), specifically moγu-°, which is attested only in the Y.Av. compound moγu.tb̰ iš-. The rising weight assumed by the priestly college of the Magi in secular activities already during the Achaemenian period promoted the preservation of this title also after the diffusion of the Avestan liturgy in Western Iran. This development also ensured that the designation of *moγ(u)- became extended to the whole family of the Zoroastrian priests following the Avestan tradition.