The attempt at reverse sinicization would probably not have been effective in any case, but it did not last long. Rebellions broke out throughout north China, many of these upheavals the backwash of the overthrow of the Northern Wei decades earlier. By 581, a new Chinese dynasty, the Sui, had unified north China, and in less than a decade, it went on to unify nearly all of China (Figure 9.1). The new Sui dynasty initiated a long period of centralized rule in China, instituting a ruling system more reminiscent of the Legalist Qin dynasty than the more Confucian Han dynasty, though most Sui offices had titles taken from the Han. It engaged in a massive program of military expansion, including allied nomadic tribesmen as well as vast numbers of Chinese recruits.
Figure 9.1 Territories of the Sui and Tang Dynasties, as Weil as Korea's Silla Kingdom, Between 589 and 907
In organizing his military, Sui Wendi, the first Sui emperor, made some significant changes to the previous systems established by the conquest dynasties. The military household class was abolished, and all families were registered as civilians. Although many families might be required to provide sons for the military, this resembled conscription rather than a separate hereditary military class. The military itself was reorganized into twelve military districts, with a trusted general in charge of each. For his mounted forces, Wendi relied primarily on steppe tribesmen, but these forces were kept on the frontiers, to be used more as a buffer than as an integral part of the Sui military.
One aspect of Wendi’s Legalism was the need not only to unify the Chinese world but to expand beyond its borders as well. In particular, he took steps to subdue the Turks on China’s northern and northwestern borders. He was able to accomplish this through diplomacy and the good fortune that, in the late sixth and early seventh centuries, the Turks were divided and quarrelsome among themselves. His policies toward the Turks were followed by his successor, who if anything was even better at playing steppe politics. But the early Sui had uneven success here and elsewhere.
In Vietnam, a successful invasion was undone by epidemics in the army; Vietnam remained a tributary state rather than coming under direct Chinese rule. Sui Wendi and his successor, Sui Yangdi, both planned to subjugate the Korean kingdom of Koguryo, and both were unsucessful despite huge investments of men and materials. Korean delaying tactics led to logistical breakdowns, exacerbated by summer rains and severe winter weather. Turkish allied cavalry units failed to show up. In the end, the massive effort destabilized the Sui rather than accomplishing the conquest of Korea. By 617, the dynasty had fallen into chaos.