 In fall 617, at Emperor Yang's orders, the general Xue Shixiong (), who was in charged of defending Zhuo Commandery, led his 30,000 men south, intending to attack Li Mi—then generally recognized as the strongest rebel leader.As Xue went through Hejian Commandery (河間, roughly modern Cangzhou, Hebei), near Dou's holdings, Dou's army became fearful and fled.Xue thus took no further precautions, believing Dou to pose no further threat.