anyone else?" Emperor Gaozong therefore became resolved. He demoted Chu to be a commandant at Tan Prefecture (roughly modern Changsha, Hunan), and then deposed both Empress Wang and Consort Xiao, putting them under arrest and creating Consort Wu, as empress (皇后, huánghòu) and the most powerful woman in the empire (天下母, Tiānxià Mǔ) instead to replace Empress Wang. (Later that year, Empress Wang and Consort Xiao were killed on orders by the new Empress Wu after Emperor Gaozong showed signs of considering their release.) Then, at Xu's suggestion, in spring 656, Emperor Gaozong demoted Li Zhong to be the Prince of Liang and created Empress Wu's oldest son Li Hong the Prince of Dai crown prince instead. In 655 as well, Emperor Gaozong commissioned the general Cheng Zhijie () to attack Ashina Helu, but while the campaign saw some victories over Western Turkic Khaganate's substituent tribes Geluolu () and Chuyue (), it was hindered by Cheng's inability to restrain his assistant Wang Wendu () from pillaging and inappropriately halting the army. After the campaign ended in early 657, both Cheng and Wang were deposed from their offices. Xianqing era (656–661) In 657, Emperor Gaozong commissioned the general Su Dingfang, who had served under Cheng Zhijie in the earlier failed campaign, to command a campaign against Ashina Helu, assisted by Ren Yaxiang and Xiao Siye (). They were joined by the Western Turkic Khaganate's leaders Ashina Mishe and Ashina Buzhen, who had submitted to Tang during Emperor Taizong's reign. The campaign caught Ashina Helu by surprise, and Su defeated him in several battles, causing him to flee to the kingdom Shi (石國, centering modern Tashkent, Uzbekistan), which arrested him and delivered him to Su, thus largely ending the Western Turkic Khaganate as an organized state. (Emperor Gaozong would try to continue the Western Turkic Khaganate's existence as a vassal stage by dividing it in half and creating Ashina Mishe and Ashina Buzhen as khans of the two halves.) Meanwhile, Xu Jingzong and Li Yifu, aligned with Empress Wu, and became strong enough to fight for power, began to carry out a campaign of reprisal on her behalf. Empress Wu, on the other hand, persuaded Emperor Gaozong to work with the removal of the chancellors appointed by Emperor Taizong to consolidate the emperor's power. In 657, they accused Han Yuan and Lai Ji of plotting treason with Chu Suiliang, who was then