Arvandrūd; From Mythological River of Ranghā, Arang and Aurvant to Tigris and Shatta Al-Arab: A Morphologic Approach

In the history of Iranian culture and civilization, the name of Arvandrūd can be seen in different historical periods. In Iranian mythology and in the holy book Avesta, the name of this river is mentioned as "Ranghā", "Arang" and "Aurvant". In the early centuries of Islam, in the Mazdayasnian religious and historical texts (in Middle Persian) the name of Arang and Arvand mentioned as "Tigris". In Shāhnāmeh and in the battle of "Fereydun and Zahak", Ferdowsi uses the Arabic word "Tigris". Mentioning the name of the Tigris in Behistun Inscription with the term "Tigre" indicates the historical background of the river in ancient times. Also, mentioning the name "Shatt al-Arab" in some historical and literary texts is controversial. Using library sources and descriptive-analytical method and by a morphological approach, the present research, for the first time, explains the most important names of Arvandrūd from ancient times to modern times, the names which have been presented in the form of mythological, historical and literary narratives. The results show that the mythological river of " Ranghā" or "Arang" is the same as Arvandrūd and it is created by Hourmazd (Ahuramazda) in a metamorphosis; and in the myth of Creation and Rain, it takes on a sacred and divine aspect. It seems that mentioning these names in Avestan and Pahlavi texts as well as Iranian national epics is a kind of celebration and revival of the ancient name of Arvandrūd.