At the end of the Sui Dynasty and the beginning of the Tang Dynasty, the Turkic forces were overwhelming, and they never flourished on the grassland. The Tang Dynasty was established, and although the national strength gradually recovered, it was beyond the strength of the Turks. In the early days, the Tang Dynasty cut the Hetao, and the Turks crossed the Yin Mountain to the south, threatening the Tang capital. In the seventh year of Tang Wude, in the face of the southern invasion of the Turks, Li Shimin vowed to pacify the northern Xinjiang for ten years, and finally repelled the Turks in the Battle of Wulongban.
After Li Shimin ascended the throne, he remembered the old saying, the shame of the Weishui Alliance, the Tang Dynasty and the Turks were friendly, but they planned to fight back in their hearts. Zhenguan three years, five years since the oath, the Eastern Turks are as strong as ever, and the road to pacification in the Tang Dynasty is difficult.
However, in the past three years, Datang has not only made full military and financial preparations, but also quietly launched a diplomatic intelligence network. Tang Dynasty envoys sent envoys to the Turks, and at the same time worked part-time intelligence work, meticulously probing the situation in the grasslands. Chang'an, Honglu Temple has constant foreign exchanges, secretly collects intelligence, befriends Turkic nobles, and secretly responds.
In the frontier, Zhang Gongjin monitored the dynamics of the grassland and implemented a divisive plan. The Eastern Turks were in civil strife, and the Tang forces quietly intervened. In the second year of Zhenguan, the Tang Dynasty took advantage of the chaos to clear the northern border and pave the way for a counterattack against the Turks.
The diplomatic envoys of the Tang Dynasty laid out the grassland, the Xue Yantuo tribe was canonized by the Tang Dynasty, and the four directions of the southeast, northwest and southeast formed a blockade against the Turks. The Turks fought among themselves, and the Turki Khan asked for help in vain, and finally surrendered to the Tang. Jieli Khan was isolated.
In August of the third year of Zhenguan, Zhang Gongjin, the governor of Daizhou, reported that the Turks could attack. Tang Ting decided to go on the Northern Expedition, Li Jing was in charge, Zhang Gongjin was deputy, and the Tang Dynasty finally fought back. After years of Taoguang cultivation, Datang has shown its edge.