The Effects of the Muslim Conquest on the Persian Population of Iraq
By Michael G. Morony
Iran, Vol. 14 (1976)
Introduction: Persians have always been a minority in Iraq, but for most of classical and late antiquity they were a ruling minority. Apart from the concentration of Persians along the foothills of the Zagros mountains and the upper reaches of the tributaries of the Tigris, which was merely an extension of the Persian settlement on the Iranian plateau, the large-scale Persian immigration into the Mesopotamian plain began with the rise of the Sasanian state in the third century A.D. Drawn to the court at Ctesiphon, posted as administrators and garrisons to positions in the western quarter of the empire, or brought in as agricultural labour, the Persian presence in Iraq was largely the result of the military, administrative, and economic requirements of the Sasanians.
Unfortunately, there are no reliable figures for the size and distribution of the Persian population in Sasanian Iraq, but it is possible to approach questions of demographic change by comparing settlement patterns and by noting the shifts in population that included Persians. The Sasanian policy of establishing an ethnic Persian presence in the west implemented by transfers of population led to a demographic pattern of settlement along the outer edge of southern and western Iraq as permanent frontier garrisons, in the major cities of Iraq by the families of aristocratic Persians, and in villages in the Sawdd. This movement began in the third century with the settlement of a permanent garrison at Anbar followed by the settlement of 12,000 upper-class Persian families (ahl bait) from Istakhr and Isfahdn at Nasibin when that city was taken from the Romans in 363 A.D.