Emperor Taizong of Tang (r. 626-649), the second emperor of Chinese dynasty Tang Dynasty, early in his reign, had allied with Xueyantuo, a vassal of the powerful Eastern Tujue (Göktürk) Khanate, against Eastern Tujue, who Tang had defeated in 630.

Upon Eastern Tujue's defeat, Xueyantuo's Zhenzhu Khan Yi'nan had taken over Eastern Tujue's former territory, and while he is formally submissive to Tang, he has been expanding his own strength.

When Emperor Taizong tries to restore Eastern Tujue in 639 under the Qilibi Khan Ashina Simo (also known as Li Simo) to counteract the rise of Xueyantuo power, Xueyantuo engages in multiple battles with the newly restored Eastern Tujue, in order to prevent this return.

The major Tang general Li Shiji temporarily comes to protect Eastern Tujue against Xueyantuo and defeates the Xueyantuo forces in 641.

But in 644, with Emperor Taizong occupied with a campaign against Goguryeo, Xueyantuo forces launch a new campaign and defeat Eastern Tujue, forcing Ashina Simo to flee back to Tang.

Subsequently, Goguryeo seeks aid from Xueyantuo, but Yi'nan avoids further conflict, wanting to avoid direct battle with Tang.

After Yi'nan's death in 645, however, his son, the Duomi Khan Bazhuo begins heavily battling Tang forces.

In 646, Tang forces counterattack, and after they defeat Bazhuo, Xueyantuo's vassal Huige rises and kills him.

His cousin, the Yitewushi Khan Duomozhi, surrenders to Tang forces, ending Xueyantuo.