伏允
Throughout the reign of Emperor Taizong's father Emperor Gaozu, there were repeated cycles of Tuyuhun, then ruled by the Busabo Khan Murong Fuyun, making incursions into the modern Sichuan and southern Gansu regions and offers of peace by both sides, never longstanding. These incursions continued after Emperor Taizong became emperor in 626—although they appeared to decrease in frequency, as the only incursions recorded in the Chinese chronicle "Zizhi Tongjian" were in 628, when Tuyuhun forces attacked Min Prefecture (岷州, roughly modern Dingxi, Gansu), and 632, when Tuyuhun forces attacked Lan Prefecture (蘭州, roughly modern Lanzhou, Gansu). It was said that, with regard to Tuyuhun's generally hostile attitude toward Tang, that Murong Fuyun had, in his old age (although it is not known what his age was at this point), taken the posture at the advice of his strategist, the Prince of Tianzhu.