interfluve was the convergence and partial merging of the settled, Iranian-speaking and Turkic-speaking, with the nomadic, mainly Turkic-speaking population. Turkic and Chinese migration into Central Asia occurred during the Chinese Tang Dynasty, and Chinese armies commanded by Turkic generals stationed in large parts of Central Asia. But Chinese influence ended with the An Lushan rebellion. During the 9th and 10th centuries, Transoxiana was ruled by the Persian Samanid Dynasty. From the 11th century on, Transoxania was under the rule of Turkic Kara-Khanid Khanate, their arrival in Transoxania signalled a definitive shift from Iranian to Turkic predominance in Central Asia. Kara-Khanid ruler Sultan Satuq Bughra Khan was the first Turkic ruler to convert to Islam, most people of Central Asia soon followed. In the 12th century, Transoxania was conquered by Qara Khitai (Western Liao), a sinicized Khitan dynasty, they brought to Central Asia the Chinese system of government. In the 13th century, Kara-Khanid Khanate was destroyed by the Turkic Khwarazmian dynasty, a former vassal of the Qara Khitai. Although Turko-Mongol infiltration into Central Asia had started early, and the influence of the Turkic tribes was felt in Khwarazm before the campaigns of the Mongols, after the beginning of the Chingizid rule, bilingualism became more common. It is generally believed that these ancient Indo-European-speaking peoples were linguistically assimilated by smaller but dominant Turkic-speaking groups while the sedentary population finally adopted the Persian language, the traditional lingua franca of the eastern Islamic lands. The language-shift from Middle Iranian to Turkic and New Persian was predominantly the result of an elite dominance process. This process was dramatically boosted during the Mongol conquest when millions were either killed or pushed further south to the Pamir region. Peter B. Golden listed three basic ethnic elements contributing to the Uzbeks' ethnogenesis: the Turkicized, formerly Iranian-speaking sedentary Sarts, a composite population including both Iranians (Sakas, Sogdians, Khwarzamians, Kushano-Bactrians) and some Arab elements; the pre-Uzbek amalgam of nomadic Türk(î) or Chagatays, who consisted of Karluks, Yaghmas and other tribes of the Göktürks' khaganates, and later of the Karakhanid state, Oghuzes, the Kangly-Kipchaks (particularly in the western region) and many Turkicized Mongol tribes (Barlas, Jalayir, etc.), who entered Central Asia with the Mongol and Timurid conquests and invasions. The East Kipchak-speaking "Pure Uzbeks" (Taza Özbek). The modern Uzbek language is largely derived from the Chagatai language which gained prominence in the Timurid Empire. The position of Chagatai (and later Uzbek)