the conquest strengthened tang rule over modern xinjiang, administered by the anxi protectorate, and led to tang suzerainty over the regions previously under the control of the western turks. the fall of the khaganate brought the altai mountain region under tang control and the residing three qarluq tribes were governed in newly established prefectures led by tribal chiefs, now commander-in-chiefs under the tang. another prefecture, the jinman bridle prefecture, was created for the chuyue tribes living in the southern dzungar basin. the amu darya valley, the tarim basin, and the area beyond the pamir mountains, all former suzerains of the western turks, were placed under tang control.