able to preserve his troops. In 626, when Eastern Tujue attacked again, Li Jing was made the commandant at Ling Prefecture (靈州, roughly modern Yinchuan, Ningxia), and he tried to cut off Eastern Tujue's return path, although soon Tang and Eastern Tujue made peace. It was said that at this time that Li Shimin, then engaged in an intense rivalry with his older brother Li Jiancheng the Crown Prince and fearing that Li Jiancheng might be intending to kill him, solicited advice from Li Jing and Li Shiji, and both refused to speak on the matter, drawing respect from Li Shimin for their unwillingness to be involved in an internecine struggle. In 626, Li Shimin set a show down for Li Jiancheng and another brother, Li Yuanji the Prince of Qi at Xuanwu Gate, killing them, and then effectively forced Emperor Gaozu to create him crown prince and then pass the throne to him (as Emperor Taizong). During Emperor Taizong's reign Li Jing continued to serve in Emperor Taizong's administration, and was soon made the minister of justice. In 628, in addition to that post, he also became acting Zhongshu Ling (中書令) -- the head of the legislative bureau of the government (中書省, Zhongshu Sheng), a post considered one for a chancellor. In 629, he was made the minister of war. Around the new year 630, with Eastern Tujue in internal turmoil, with its Jiali Khan Ashina Duobi attacking his nephew and subordinate khan, the Tuli Khan Ashina Shibobi (阿史那什鉢苾), Emperor Taizong commissioned Li Jing, Li Shiji, Wei Xiaojie, Li Daozong, Chai Shao (柴紹), and Xue Wanche (薛萬徹) to attack Eastern Tujue, with Li Jing in overall command. Li launched his attack in a surprise manner, from Mayi through Wuyang Range (惡陽嶺, in modern southern Hohhot, Inner Mongolia), capturing the important city of Dingxiang (定襄, in modern Hohhot). In fear, Ashina Duobi retreated to Qikou (磧口, in modern Xilin Gol League, Inner Mongolia). Li Jing then sent secret messengers to persuade his associate to surrender. One of them, Kangsumi (康蘇密), took Emperor Yang's wife Empress Xiao and her grandson Yang Zhengdao, whom Eastern Tujue had created the Prince of Sui, and surrendered to Li Jing. Ashina Duobi sent messengers to Emperor Taizong, offering to submit and to pay homage to him later, but was still considering fleeing further with his forces. Emperor Taizong sent the official Tang Jian (唐儉) as