Native Iranian population of Central Asia and the steppes part of the region, had also been turkified by the migrating Turkic tribes of Inner Asia by the 6th century A.D. The process of Turkification of Central Asia, besides those parts that today constitute the territory of the present-day Tajikistan, accelerated with the Mongol conquest of Central Asia. Mahmud al-Kashgari writes that the people who lived between Bukhara and Samarkand were Turkified Sogdians, which he refers to them as “Sogdak”.