Here again he uses the term Arab to refer to the ethnic Arabs of the Arabian Peninsula and Ajam to refer to non-Arabs in general, though it often referred to the Iranian peoples from a sedentary Persian culture on the Iranian plateau. Ibn Khaldun made a distinction between being linguistically Arabized and being culturally Arabized. Cultural Arabization to him meant adopting a tribal, Bedouin and desert lifestyle and was opposite to the sedentary, urban culture, which was inherently non-Arab. Throughout his work he makes the point that Arabs during the early Muslim expansion, were indeed de-Arabized and to some degree adopted Persian and Greek sedentary culture. Also note that in medieval Islamic literature, there were two regions known as Iraq: the Iraq-i Arab and the Persian Iraq. The Persian Iraq mentioned by Ibn Khaldun is the historic Iraq-e-Ajam (Persian Iraq) which constitutes the triangle of Isfahan, Shiraz and Hamadan.