Emperor Gong appeared to be even more powerless than his father and brother, and the power remained in Yuwen's hands. He created his wife, Princess Ruogan,
empress. Later in 554, Yuwen poisoned the deposed Emperor Fei to death. Later that year, an army dispatched by Yuwen and commanded by
Yu Jin captured rival
Liang dynasty's capital Jiangling (江陵, in modern
Jingzhou,
Hubei), capturing and executing Liang's
Emperor Yuan. In spring 555, Emperor Gong created
Xiao Cha, a nephew of Emperor Yuan, the Emperor of Liang (as Emperor Xuan), but Xiao Cha was not recognized by most of Liang generals and officials, who instead recognized
Xiao Yuanming, a candidate supported by
Northern Qi, as emperor. (Xiao Cha's state is known as the
Western Liang in history.) Later in 555, Yuwen required Tuoba Yu () the Prince of Huai'an to submit to Emperor Gong a proposal to have the imperial princes reduced in rank to dukes, of which Emperor Gong approved. In spring 556, pursuant to Yuwen's desire to reorganize the governmental structure in accordance with the
Zhou dynasty governmental structure, the imperial government was reorganized into six departments. In fall 556, while Yuwen Tai was on a tour of the northern provinces, he became ill at Qiantun Mountain (牽屯山, in modern
Guyuan,
Ningxia). He summoned his nephew
Yuwen Hu to Qiantun and entrusted the affairs of the state as well as his sons to Yuwen Hu. He soon died, and Yuwen Tai's 14-year-old son
Yuwen Jue took over his titles, while Yuwen Hu took the reins of the state. Emperor Gong was subsequently forced to create Yuwen Jue the greater title of Duke of Zhou. In spring 557, Yuwen Hu, believing that Yuwen Jue's youth meant that he needed to take the imperial title to affirm his authority, forced Emperor Gong to yield the throne to Yuwen Jue, ending Western Wei and starting
Northern Zhou. ==Death==