Shibi Khagan (r. 609 or 611–619 AD) succeeded Yami Qaghan as the second khagan of the Eastern Turkic Khaganate. Reign He succeeded Yami Qaghan in 609 or 611. From 613 to 615 he was actively supporting agrarian rebels inside China. Pei Ju had become apprehensive that khagan was becoming strong and difficult to control and had therefore suggested that Emperor Yang offer to marry a princess to the khan's brother Ashina Chiji (阿史那叱吉). Chiji shad, in fear, declined. This already brought resentment from the khagan, when Pei tricked the Shibi Khan's strategist Shishuhu (史蜀胡) into meeting him at Mayi (present-day Shuozhou, Shanxi) and then killed him, claiming that Shishuhu was planning to rebel against the khagan. Shibi Khahan, knowing that the accusation was false, became resolved to rebel against Sui. In the fall of 615, when Emperor Yang was visiting Yanmen Commandery on the northern frontier, the khagan launched a surprise attack on the area, overrunning most of its Chinese settlements. Warned by the khagan's wife Princess Yicheng — a member of the imperial family who had been well treated by Empress Xiao during an earlier visit — the emperor, empress, and their entourage escaped to the commandery seat at present-day Daixian. The Turks besieged them there on September 11. Resources in seat was small. Emperor was reported to cry out of fear seeing Yuwen suggested Emperor Yang select a few thousand elite cavalry soldiers to attempt a break out, but Su Wei and Fan Zigai (樊子蓋) persuaded Emperor Yang not to attempt this. Emperor Yang put Xiao Yu and Pei Ju in charge of planning the military counteroffensive, but was only able to get the siege lifted after he followed the advice of the empress's brother Xiao Yu and sent messengers to Princess Yicheng, who was directing military affairs at the Turkic capital in her husband's absence. She falsely informed Shibi Khagan that the Turks were under attack from the north, and so the khagan lifted the siege. During the turmoil of the later years of Yangdi's reign, he supported various local warlords in northwestern China, who claimed the title of emperor, including Li Yuan, who would go on to found the Tang Dynasty. The khagan supplied Li with 2,000 horses and 500 cavalry, who played a crucial role in the early victories of the Tang such as the Battle of Huoyi. Shibi khagan later supported Liang Shidu and