Religion in Iraq
Islam is the official state religion in the Republic of Iraq, but the constitution guarantees freedom of religion. Iraq is a multi ethnic and multi religious country with Islam, Christianity, Yazdanism, Zoroastrianism, Shabakism, Judaism, Mandaeism, Bahā'i, Ahl-e Haqq-Yarsanis, Ishikism and numerous other religions all having a presence in the country. Shia Islam is the main religion in Iraq followed by 60–65% of the population, while Sunni Islam is followed by 32–37% of the people. Many cities throughout Iraq have been areas of historical prominence for both Shia and Sunni Muslims, including Najaf, Karbala, Baghdad and Samarra.
Islam
A comprehensive 2015 demographic study of 232 countries and territories reported that 24% of the global population, or 1.8 billion people, are Muslims. Of those, it is estimated that over 75–90% are Sunni and 10–20% are Shia with a small minority belonging to other sects. Approximately 57 countries are Muslim-majority, and Arabs account for around 20% of all Muslims worldwide. The number of Muslims worldwide increased from 200 million in 1900 to 551 million in 1970, and tripled to 1.8 billion by 2015.