The first inhabitants of Iran were the Elamites, who came from Elam, first son of Shem and Faatin (Genesis 10:22), The son of Noah (Genesis 10:1), of the Black sea, with woolly hair. And after them came the Kassites, The Kassites, are Indo European people that inhabited the Mountain east of Babylon. The Royal Family of Assyria. They entered Babylon by a process of peaceful penetration. Then their power and their Dynasty ruled from Ca. 1650 to Ca. 1175 B.C. Iran was also known as Persia from the Ancient Greek name "Persis" However, The Iranian government requested use of the correct name Iran. The Persians remains remained under the rule of the Median Kings until about 550 B.C. Then Cyrus The Great, A Persian King, revolted and overthrew the Median rule.
In order to make a long story short, Modern Day Iranians are not dark skinned, woolly-haired people of the original seed, However, a mixture of various different Tribes, such as Greeks, Europeans Romans, Mongols, Turks, and Russians. Their Islam is definitely not the Pure Islam, the was taught under Muhammad, Son of Abdullah and Amin.
