As recorded by the Pahalavi speaking historians of the Sassanid era as well as the early Islamic writers, Abarshahr or Ram Shahrestan was the oldest city of the Sistan Province of Iran. In Avesta (the sacred book of the Zoroastrians), “Ram” or Raman, meaning peace and tranquility, is the god of wind, who has other names like “Viyou” and “Vayeveh” and is the guardian of the 21st day of each month. Avesta also refers to him as “the owner of a good pasture” whose name often accompanies the name of “Izad Mehr”; and Yasht XI (Ramyasht) has been dedicated to his praise and admiration. He is called Ram because he gives peace and tranquility to the whole creation (Doostkhah, 1375, 99). Thus, Ram Shahrestan is “the city of Ram”, the god of wind. In the Sistan Province this natural phenomenon is referred to as the “120 day winds”, which affects the nature as well as the life of the people in this region by blowing continuously. The small dissertation of Shahrestan-haye Iran, regards the Turanian king, Afrasiab, as the founder of Shahrestan who also destroyed it and extinguished the Pirouz fire of the Karkuk after having sexual relationship with Sependar-maz (the goddess of earth). Following this event, Kaikhosrow rebuilt the city and later on Ardashir, the son of Papak, completed its construction. (Hedayat, 1348: 265–266) Jeihani, Estakhri, Ibn-e Howqal and Jowzjani are among the other geographers who have briefly referred to the name of Ram Shahrestan in their works.
