Islam in Iran
Before the Islamic conquest, the Persians had been mainly Zoroastrian, however, there were also large and thriving Christian and Jewish communities. Eastern Iran (what is now Afghanistan) was predominantly Buddhist. There was a slow but steady movement of the population toward Islam. When Islam was introduced to Iranians, the nobility and city-dwellers were the first to convert, Islam spread more slowly among the peasantry and the dihqans, or landed gentry. By the late 11th century, the majority of Persians had become Muslim, at least nominally.