In spring 621, with Dou approaching, Li Shimin advanced east to the important Hulao Pass and held position there. When Dou engaged him, he defeated Dou and captured him. In fear, Wang surrendered. Emperor Gaozu executed Dou while exiling Wang (although Wang was subsequently killed by the Tang general Dugu Xiude (獨孤修德), whose father had been executed by Wang). Wang's Zheng state and Dou's Xia state were annexed by Tang, although former Xia territory soon rose under the leadership of Dou's general Liu Heita, who declared himself the Prince of Handong, and modern Shandong, which had been controlled by the agrarian leader Xu Yuanlang but had successively submitted to Zheng and then to Tang, rose as well under Xu, who declared himself the Prince of Lu.