When he captured Tianshui, he gathered all the rich men and hung them upside down, pouring vinegar into their nostrils to force them to surrender their treasure.
Xue Ju often warned him, "You are capable of great things, but you are strict and cruel, with no grace to others.
(Soon, after hearing that Emperor Yang had been killed in a coup led by Yuwen Huaji in Jiangdu (江都, in modern Yangzhou, Jiangsu), Li Yuan had Yang You yield the throne to him, establishing the Tang dynasty as its Emperor Gaozu.)
Further, Hao Yuan mourned Xue Ju so greatly that he himself grew ill and died.
Xue Rengao was forced to withdraw into the city of Gaozhi (高墌, in modern Xianyang as well), and once he did, his soldiers began surrendering to Li Shimin en masse.
Li Shimin spared Xue Rengao's brothers[6] and Zong, incorporating them into his army as officers.