Waw, you can write the whole hub about this.
Iran is one of the countries that has a long history behind it.
The name of Iran (ایران) is the Modern Persian derivative from the Proto-Iranian term Aryānā,, meaning "Land of the Aryans". The term Ērān is found to refer to Iran in a 3rd-century Sassanid inscription, and the Parthian inscription that accompanies it uses the Parthian term "aryān" in reference to Iranians.
The Persians never went anywhere, they simply evolved together with their history.
Religion in Iran is dominated by the Twelver Shia branch of Islam, which is the official state religion and to which about 90% to 95% of Iranians belong. About 4% to 8% of Iranians belong to the Sunni branch of Islam, mainly Kurds and Iran's Balochi Sunni. The remaining 2% are non-Muslim religious minorities, including Bahá'ís, Mandeans, Hindus, Yezidis, Yarsanis, Zoroastrians, Jews, and Christians.