Before Arias’ coming to the Iranian plateau, tribes like Elamite, Tapoyrian, and Kadousian and Amard anlivedin different areas of it. For seizing native land, Arias fought a hardand bloody war with them and due to the ethnic, territorial and religious differences they had with indigenous ethnic groups, they called these groups as Bogies and Mazenis as Bogies of Mazandaran. Although two or three lands were in mythological and epic texts called as Mazandaran, undoubtedly, Tabarestan or the current Mazandaran which, in Shahnameh, has been referred frequently to as the Elm Grove has been one of them. The main cause of this naming Mazandaran indigenous ethnic groups as Bogies has concerned the Zoroastrians’ religious fervor, who called as Bogies and irreligious everybody who had a religion other than theirs. Thus, Bogy has the meanings of courageous and brave, strong and powerful, sullen and irreligious, huge and strangely-born and beside the words of alley and Kia, implies Ancientness of Mazandaran Another reason for calling Mazandaran people as Bogies has been that Zoroastrians tried to destroy their cultural identity by attributing bogie-worshipping and sorcery and witch craft to them, and to show destroying them or making them slaves as acceptable and approved, while according to the very mythological and epictexts, not only there is no doubt about Mazandaran Bogies being human, but also they were much more cultured and civilized than invasive Arias in terms of cultureand civilization and Arias learnt many components and representations of culture from Mazandaran Bogies, among which are the language, writing, to read and to write; in addition, Mazandaranis’ expertise in architecture and music made them urban people in a way that Arias had to learn components of culture and civilization and the customs of urbanity from them.