Peninsula and unified the parts of the peninsula south of the Taedong River. In 677, he bestowed on Goguryeo's former King Bojang, Go Jang, the titles of Prince of Chaoxian and commandant of Liaodong, giving him the forcibly removed Goguryeo people. He also bestowed on Buyeo Yung the title of Prince of Daifang and commandant of Xiongjin—with the intent of letting Go Jang and Buyeo Yung to rebuild Goguryeo and Baekje as loyal vassals to counteract Silla. To accommodate these movements, the Protectorate General was further moved to Xincheng. (Buyeo Yung was not able to make any headway in leading his people back to Baekje territory, while Go Jang tried to break away from Tang rule in alliance with the Mohe; when this was discovered, Emperor Gaozong and Empress Wu recalled him to Chang'an and exiled him to Qiong Prefecture.) Meanwhile, Tang had to endure multiple attacks from the Tibetan Empire, and in 677, he commissioned Liu Rengui, then a chancellor, to take up defense position at Taohe Base (洮河軍, in modern Haidong Prefecture, Qinghai), to prepare a counterattack against the Tibetan Empire. However, Liu's proposals were repeatedly blocked by another chancellor, Li Jingxuan. In order to retaliate against Li Jingxuan, even though Liu knew that Li Jingxuan was not capable in military matters, he nevertheless recommended that Li Jingxuan take over for himself, and despite Li Jingxuan's attempt to decline, Emperor Gaozong commissioned Li Jingxuan to command the army against the Tibetan Empire. In fall 678, Li Jingxuan's forces engaged Tibetan forces commanded by Lun Qinling, and was soundly defeated, with Li Jingxuan's assistant Liu Shenli () captured by the Tibetan Empire. Li Jingxuan was only able to escape after being protected by the ethnically Baekje general Heichi Changzhi. Tiaolu, Yonglong, Kaiyao, Yongchun, and Hongdao eras (679–683) Meanwhile, the Western Turkic Khaganate chieftain Ashina Duzhi had claimed the title of Shixing Khan and was allied with another chieftain, Li Zhefu (), and they pillaged Anxi (i.e., Suyab). Emperor Gaozong was ready to commission an army against Ashina Duzhi and Li Zhefu, but the official Pei Xingjian (), who had previously served as secretary general at Xi Prefecture (西州, roughly modern Turfan Prefecture, Xinjiang), opposed—instead proposing that a small detachment be announced to escort the Persian prince Narsieh back to Persia to contend for regal title. Emperor Gaozong agreed and put Pei in charge of the detachment. When Pei arrived