The Xue and the Yantuo were initially two separate tribes.

The Xue appeared earlier as Xinli but were not referred to again until the seventh century.

After Yishibo, the Xueyantuo establish a short-lived Qaghanate over the steppe under Zhenzhu Khan, his son Duomi Khan and nephew Yitewushi Khan, the last of which will eventually surrender to the Chinese.

The Xueyantuo ally with the Chinese on March 27, 630, to defeat the Eastern Qaghanate in the Yin Mountains.

Ashina Duobi, Eastern Gokturk Illig Qaghan, escapes but on May 2 is handed over to the Chinese by his subordinate qaghan.

The Tang dynasty in 630 defeats Illig Qaghan, and the Xueyantuo effectively take over control of the Eastern Gokturks, former territory, at times submissive to Tang and at times warring with Tang and the subsequent khan of the Eastern Gokturks that Tang supports, the Qilibi Khan Ashina Simo.

The Aru-Kagan (Chinese Helu) of the Eastern Turkic Kaganate is captured in 630 by the Chinese.

His heir apparent, the "lesser Khan" Khubo, escapes to Altai with a major part of the people and thirty thousand soldiers.

He conquers the Karluks—a branch of the Turgesh or aboriginal Altaians—in the west and the Kyrgyz in the north, and takes the title Ichju Chebi Khan.

…following the Tian Shan westward in 630 to arrive in Turpan.

Here he meets the king of Turpan, a Buddhist who equips him further for his travels with letters of introduction and valuables to serve as funds.

Moving further westward, …

…Xuanzang escapes robbers to reach Yanqi, then …

…tours the non-Mahayana monasteries of Kucha.

Further west, …

…Xuanzang passes Aksu before turning northwest …

…to cross the Tian Shan's Bedel Pass into modern Kyrgyzstan.

Xuangzang skirts Issyk Kul …

…before visiting Tokmak on its northwest, and meets the great Khan of the Western Türk, whose relationship to the Tang emperor is friendly at the time.

After a feast, …

…Xuanzang continues west then southwest to Tashkent, capital of modern Uzbekistan.

From here, …