ABSTRACT
The first phase begins with the gradual infiltration of Turkish ethnic elements within the northeastern borders of the Islamic world, the Gurgan-Dihistan region to the southeast of the Caspian Sea, Khwarazm, Transoxania, and possibly also eastern Afghanistan. In the first three centuries of Islam, however, it is clear that there was some settlement of Turks on the borders of the Iranian lands in Transoxania and Khwarazm, if only as part of the symbiosis prevailing along these frontiers of the sedentary agricultural economy and the nomadic pastoralist one. Some Turkish historians have seen Turks lurking everywhere in that part of the world. The Islamic and Turkish worlds also marched side-by-side in the Dihistan steppes to the southeast of the Caspian, where defensive walls existed from at least Sasanid times. The Turkish takeover of military, and increasingly, political, power, continued as the authority of the 'Abbasid Caliphate diminished and became confined to central 'Iraq.
