Then, reversing his father's peaceful policy with the Tang dynasty, Duomi Khan immediately started incursions into their territory.
This drew a heavy response from Emperor Taizong of Tang, who sent the generals Qiao Shiwang (喬師望), Zhishi Sili (執失思力), and Li Daozong to defend.
They proved too strong for Duomi Khan's attacks, so he fled.
As of 638, with Yi'nan having more than 200,000 soldiers under him, Yi'nan was said to have divided his army between Bazhuo and Jialibi, having Bazhuo command the army to the south and Jialibi to the north; it was further said that Emperor Taizong of Tang, in order to foster dissent between the brothers, created them both subordinate khan titles under Yi'nan and awarded them drums and banners, ostensibly to honor them.
[2] In a reference that was either referring to the same event or not, Bazhuo and Yemang were described to have been both created subordinate khan titles, at Yi'nan's request, with Yemang given the eastern part of the khanate to govern over various tribes, with the title of Tulishi Khan, and with Bazhuo given the western part of the khanate to govern over the Xueyantuo people, with the title of Siyehu Khan.