THIS IS THE HISTORY:
"Arab Muslims conquests have been variously seen in Iran: by some as a blessing, the advent of the true faith, the end of the age of ignorance and heathenism; by others as a humiliating national defeat, the conquest and subjugation of the country by foreign invaders. Both perceptions are of course valid, depending on one's angle of vision…
Iran was indeed Islamized, but it was not Arabized. Persians remained Persians. And after an interval of silence,
Iran reemerged as a separate, different and distinctive element within Islam, eventually adding a
new element even to Islam itself. Culturally, politically, and most remarkable of all even religiously,
the Iranian contribution to this new Islamic civilization is of immense importance. The work of Iranians can be seen in every field of cultural endeavor, including Arabic poetry, to which poets of Iranian origin composing their poems in Arabic made a very significant contribution. In a sense, Iranian Islam is a second advent of Islam itself, a new Islam sometimes referred to as Islam-i Ajam.
It was this Persian Islam, rather than the original Arab Islam, that was brought to new areas and new peoples: to the Turks, first in Central Asia and then in the Middle East in the country which came to be called Turkey, and of course to India.
The Ottoman Turks brought a form of Iranian civilization to the walls of Vienna."
Muslim conquest of Persia - Wikipedia, the free encyclopedia