Ju. He promoted Xue Rengao, Xue Renyue, and Zong to princes. As emperor In fall 617, Xue Ju claimed the title of Emperor of Qin. He created his wife Lady Ju empress, and he created Xue Rengao crown prince. Xue Rengao subsequently captured Tianshui, and Xue Ju moved his capital to Tianshui. As Xue Rengao was fierce but often overly cruel to those he captured, Xue Ju often warned him, "You are capable of great things, but you are strict and cruel, with no grace to others. One day you will surely destroy the state I established and our clan." According to traditional historical accounts, however, Xue Ju himself was also cruel, often killing soldiers he captured, and also often cut off their tongues and noses, and therefore did not gain as much following as he hoped. When he sent Xue Renyue south to try to capture lands in modern Sichuan, Xue Renyue was blocked by Xiao Yu the governor of Hechi Commandery (河池, in modern Baoji, Shaanxi) and unable to advance. He also sent his general Chang Zhongxing () west of the Yellow River to attack Li Gui, who had by then seized the territory west of the Yellow River. Chang, however, was defeated by Li Gui's general Li Yun (), and the entire army was captured by Li Gui, although Li Gui released them back to Xue Ju. Around the new year 618, Xue Ju sent Xue Rengao to attack Fufeng Commandery (扶風, also in modern Baoji), but Xue Rengao was blocked by the rebel leaders Li Hongzhi (), who had claimed the title of Emperor of Chu, and Tang Bi (), who had claimed the title of Prince of Tang under Li. Xue Ju sent messengers to persuade Tang to submit, and Tang killed Li and then offered to surrender. Instead, Xue Rengao attacked Tang and seized his troops. Xue Ju then proceeded himself to Fufeng, intending to next attack the Sui capital Chang'an, which had been captured by the Sui general Li Yuan, who declared Emperor Yang's grandson Yang You the Prince of Dai emperor (as Emperor Gong). Li Yuan sent his son Li Shimin against Xue Rengao, and Li Shimin dealt Xue Rengao a major defeat. Xue Ju, in fear, asked his officials, "Since ancient times, were there emperors who surrendered?" Chu Liang () cited the examples of Zhao Tuo, Liu Shan, and Xiao Cong.