"The third important feature which developed in the early formative centuries of Islam relates to the heritage of Persia or cajam as the Arabs called it. Hindu or Buddhist India was not conquered until the thirteenth century and parts of it remained outside of Muslim control until as late as the sixteenth century. Similarly, the Byzantine state was not fully conquered (by the Turks) before the mid-fifteenth century. But Persia was conquered in its entirety in the seventh century and by the eleventh century had already largely converted to Islam. It is not surprising therefore that of the three metropolitan classical traditions of India, Greece and Persia it was Persia that resurfaced with an integral identity within the Islamic context.10 The Persian imperial tradition could not persist anywhere outside Islam and as a result a vigorous Persian resurgence occurred within it. From its Arab roots the Islamic conquest state then shifted to a Persianized foundation."
January 1, 1970
https://en.wikiquote.org/wiki/Persianization