Xiao Yu - During Emperor Yang's Reign

During Emperor Yang's Reign

In 604, Emperor Wen died—a death that traditional historians generally believed to be a murder ordered by Yang Guang but admitted a lack of direct evidence—and was succeeded by Yang Guang (as Emperor Yang). Xiao Yu, whose sister Crown Princess Xiao became empress, was made a military recruiting officer. When, at one point, Xiao Yu became suddenly ill, he ordered that no medical treatment be carried out, believing that this would be a good time for him to be relieved from governmental service. However, when Empress Xiao heard this, she visited him and rebuked him, pointing out that this kind of behavior might in fact bring punishment from Emperor Yang. After he recovered, he became more interested in governmental service, and was at one point made the Neishi Shilang (內史侍郎), the assistant head of the legislative bureau of government, and Emperor Yang entrusted him with many secret matters, as Xiao Yu was his brother-in-law. However, later on he was demoted because he often gave suggestions that offended Emperor Yang.

In 615, when Emperor Yang was visiting Yanmen (雁門, in modern Xinzhou, Shanxi), on the northern border, Eastern Tujue's Shibi Khan, Ashina Duojishi, launched a surprise attack and put Yanmen under siege. Emperor Yang panicked and did not know what to do. Xiao Yu, who had accompanied Emperor Yang to Yanmen, suggested that messengers be sent to Ashina Duojishi's wife, the Sui princess Princess Yicheng, as Tujue customs dictated that the khan's wife be in charge of military matters at home while he was away. Princess Yicheng subsequently sent false information to Ashina Duojishi, stating that Eastern Tujue was under attack from the north, and Ashina Duojishi lifted the siege. However, after the siege was lifted, Emperor Yang, instead of rewarding Xiao Yu, became embarrassed, stating, "Tujue forces were simply being rebellions and lacked tactical cohesion, and would have soon scattered. Just because they did not do so immediately, Xiao Yu was frightened; this is unforgiveable." He demoted Xiao Yu to the governorship of Hechi Commandery (河池, in modern Baoji, Shaanxi) and immediately ordered him to get on his way. When Xiao Yu got to Hechi Commandery, there were agrarian rebels in the mountains, numbering over 10,000, whom the commandery government was unable to control. Xiao Yu reorganized the commandery militia and attacked them, forcing them to surrender. Subsequently, when Xue Ju rebelled at Jincheng Commandery (金城, roughly modern Lanzhou, Gansu) and attacked east, Xiao Yu blocked Xue's path, and Xue was not able to advance further at that point.