most dominant ethnic group in Central Asia. To handle and avoid any threats posed by the Turks, the Sui government repaired fortifications and received their trade and tribute missions. They sent royal princesses off to marry Turkic clan leaders, a total of four of them in 597, 599, 614, and 617. The Sui army intervened in Turks’ civil war and stirred conflict amongst ethnic groups against the Turks. As early as the Sui dynasty, the Turks had become a major militarised force employed by the Chinese. When the Khitans began raiding north-east China in 605, a Chinese general led 20,000 Turks against them, distributing Khitan livestock and women to the Turks as a reward. On two occasions between 635 and 636, Tang royal princesses were married to Turk mercenaries or generals in Chinese service. Throughout the Tang dynasty until the end of 755, there were approximately ten Turkic generals serving under the Tang. While most of the Tang army was made of fubing(府兵) Chinese conscripts, the majority of the troops led by Turkic generals were of non-Chinese origin, campaigning largely in the western frontier where the presence of fubing(府兵) troops was low. Some "Turkic" troops were nomadisized Han Chinese, a desinicized people. Civil war in China was almost totally diminished by 626, along with the defeat in 628 of the Ordos Chinese warlord Liang Shidu; after these internal conflicts, the Tang began an offensive against the Turks. In the year 630, Tang armies captured areas of the Ordos Desert, modern-day Inner Mongolia province, and southern Mongolia from the Turks. After this military victory, Emperor Taizong won the title of Great Khan amongst the various Turks in the region who pledged their allegiance to him and the Chinese empire (with several thousand Turks traveling into China to live at Chang'an). On June 11, 631, Emperor Taizong also sent envoys to the Eastern Turkic tribes bearing gold and silk in order to persuade the release of enslaved Chinese prisoners who were captured during the transition from Sui to Tang from the northern frontier; this embassy succeeded in freeing 80,000 Chinese men and women who were then returned to China. While the Turks were settled in the Ordos region (former territory of the Xiongnu), the Tang government took on the military policy of dominating the central steppe. Like the earlier Han dynasty, the Tang dynasty, along with Turkic allies like the Uyghurs, conquered