In 646, during the reign of Yi'nan's son and successor, the Duomi Khan Bazhuo, Xueyantuo fell into a state of confusion due to a combination of attacks by the Tang dynasty, misrule by Bazhuo, and rebellions by the Huige.
Some 70,000 people fled west and supported Duomozhi as the Yitewushi Khan.
Under Duomozhi, they returned east to their old territory, but, with Huige having taken much of the old Xueyantuo territory, Duomozhi soon renounced the title of khan, sending an emissary to Tang to request permission to move to the area north of the Khangai Mountains.
Li soon arrived at the Khangai, and Duomozhi's assistant Tizhen (梯真) surrendered.
Duomozhi himself would die before Emperor Taizong's death in 649 and was said to have been mourned with honor.