the general Wang Gui () were said to have suggested that Emperor Wu execute Yang Jian, but Emperor Wu resisted. Still, Yang Jian heard rumors and tried to hide his own talent to avoid trouble. It was not until 575 when Emperor Wu involved Yang Jian in a major campaign against rival Northern Qi. Yang Jian also participated in the 576–577 campaign that saw Emperor Wu being able to destroy Northern Qi and seize its territory. In 578, Emperor Wu died, and Yuwen Yun took the throne as Emperor Xuan. Emperor Xuan immediately began to show erratic behavior, and while he created Yang Jian's daughter Crown Princess Yang empress, he suspected Yang Jian deeply, although he made Yang Jian the minister of defense. In 579, Emperor Xuan passed the throne to his young son Yuwen Chan (by his concubine Consort Zhu Manyue) (as Emperor Jing) and became retired emperor (with the atypical title of "Emperor Tianyuan" (Tianyuan Huangdi), but continued to exercise imperial powers. On one occasion, he became so suspicious of Yang Jian that he stated to Empress Yang, "I will surely slaughter your clan!" He then summoned Yang Jian to the palace, with instructions to kill him if his expressions betrayed any worries, but Yang Jian arrived without showing any unusual emotions, and avoided being killed. On another occasion, Empress Yang displeased Emperor Xuan, and Emperor Xuan ordered her to commit suicide. When Duchess Dugu heard this, she went to the palace to beg Emperor Xuan's forgiveness, and Emperor Xuan eventually spared Empress Yang. Regency In summer 581, with Emperor Xuan intending to conquer Chen Dynasty, he sent Yang Jian to be the commandant at Yang Province (揚州, roughly modern Lu'an, Anhui) to prepare for the campaign against Chen. Before Yang Jian could depart, however, Emperor Xuan suddenly grew seriously ill. Two of Emperor Xuan's close associates, Liu Fang () and Zheng Yi (), who were friends of Yang's, summoned Yang to the palace to prepare to serve as regent, overriding the desire of another closet associate, Yan Zhiyi (), to have Emperor Xuan's uncle Yuwen Zhao () the Prince of Zhao appointed regent. Emperor Xuan soon died, and Zheng and Liu issued an edict in Emperor Xuan's name appointing Yang regent. Yang immediately pleased the officials at the capital by abolishing the wastefulness and cruel policies of Emperor Xuan, and he himself demonstrated both hard work and