People who living in western Asia were the First residents of IRAN. When the Aryans arrived, they gradually started mingling with the old native Asians. Aryans were a tributary of the people today known as the Indo-Europeans, and are believed to be the grandfathers of the people of present India, Iran, and most of Western Europe.
Recent discoveries show that, centuries before the rise of earliest culture in Mesopotamia, Iran was inhabited by humans. But the written history of Iran dates back to 3200 B.C. and begins with the early Achaemenian, The dynasty that blossomed under the first Iranian world empire.