Following the Muslim conquest, however, Islamization of the population occurred. During the Median to the Sasanian eras, Zoroastrianism and Manichaeism were Iran's dominant religions. The religious demographics of the country were different in the past. The remaining population includes Christians, Zoroastrians, Jews, Bahais, and others. Only 4 to 8% of the Iranian Muslims are Sunni Muslims. 90 to 95% of the Iranian population adhere to this religion.
Twelver Shia Islam is the official state religion of Iran. Iran Is One Of The Few Muslim Countries With Shia Muslims As A Majority Later, the region was ruled by the Hellenistic states, Parthian Empire, Sasanian Empire, and finally the Arab Muslims in the 7th century CE who ruled for several centuries.
Iran was part of the Achaemenid Empire or the First Persian Empire from about 550 BC to 330 BC. The Elamite kingdoms in the 4th millennium BCE were some of the oldest civilizations in the world. Iran Is The Birthplace Of One Of The World's Oldest Civilizations Below is a list of some of the most interesting facts about Iran. Iran has great ethnic diversity and some of the most spectacular human-made creations. Hundreds of empires including some of the ancient world's most powerful ones have ruled in Persia and left their mark in the art, architecture, and culture of the country. The Islamic Republic of Iran, also called Persia, is a Western Asian country with a population of 82 million.