As part of their agreement, Xiang Yu released Lü Zhi and Liu Bang's family and returned them to Liu. Lü Zhi was given the title of "Queen Consort of Han" (). Liu Bang later renounced the truce and attacked Xiang Yu, eventually defeating the latter at the Battle of Gaixia in 202 BC and unifying China under his rule. Liu Bang proclaimed himself Emperor of China and established the Han Dynasty. He instated Lü Zhi as his empress and their son Liu Ying as crown prince. Even after Emperor Gaozu (Liu Bang)'s victory over Xiang Yu, there were still unstable areas in the empire, requiring the new government to launch military campaigns to pacify these regions thereafter. Gaozu placed Empress Lü Zhi and the crown prince Liu Ying (Lü Zhi's son) in charge of the capital Chang'an and making key decisions in court, assisted by the chancellor Xiao He and other ministers. During this time Lü Zhi proved herself to be a competent administrator in domestic affairs, and she quickly established strong working relationships with many of Gaozu's officials, who admired her for her capability and feared her for her ruthlessness, after the war ended and Emperor Gaozu returned, she remained in power and she was always influential in very of the country's affairs. Lü Zhi is known for her roles in the deaths of Han Xin and Peng Yue, two of Emperor Gaozu's subjects who contributed greatly to the founding of the Han Dynasty, of whose military capabilities both she and her husband had been apprehensive . In 196 BC, Gaozu left the capital Chang'an to suppress a revolt in Julu (within present-day Pingxiang County, Xingtai, Hebei) started by Chen Xi, the Marquis of Yangxia. A year before, Chen Xi met Han Xin before departing from Chang'an for Julu, and it was alleged that Han Xin was involved in the rebellion. Lü Zhi became wary of Han Xin, and after consulting the chancellor Xiao He, she had Xiao summon Han to meet her in Changle Palace. There, the empress had Han Xin taken by surprise, captured and subsequently executed in a torturous manner. Lü Zhi also ordered Han Xin's family and relatives to be put to death as well. When Gaozu was putting down Chen Xi's revolt, he requested reinforcements from Peng Yue but the latter claimed that he was ill and sent his subordinates to assist Gaozu instead.