This chapter explains how the imperial urban system expanded into south China. After the fall of the Han Dynasty, fighting in the north caused southern migration, particularly after the An Lushan Rebellion in 755. This led to the growth of commercial cities in the Lower Yangzi Delta, which were linked to the northern capitals via the Grand Canal after the reunification of China under the Sui Dynasty. At the same time, Chinese cities were linked to the medieval international world over land along the Silk Road, and over sea via Guangzhou. In northern capitals, which reflected the influence of the Kaogongji, cities continued to be walled and divided into wards. However, in the Lower Yangzi Delta commercial cities were more open plan. Meanwhile, the arrival of Buddhism and Daoism into China brought monasteries and temples into cities, while monks began to take responsibility for aspects of urban governance along with imperial officials. Wards divided cities socially as well as physically. The wealthy enjoyed lavish lifestyles, built palaces and mansions, donated to monasteries, and constructed gardens. Goods and people from outside China made cities more cosmopolitan, and writers reflected on this and other aspects of urban life in their poetry.

Between 643 and 668 CE, East Asia was engulfed by a war that drew in nearly every state in the region. During the preceding centuries, peripheral states used tribute and investiture relations to balance competing Chinese empires against each other, but the unification of China under the Sui disrupted this strategy. As tension emerged between Koguryŏ and the Chinese empires, Silla and Paekche repeatedly sought to advance their interests by drawing the Sui and Tang into conflicts on the Korean peninsula. The result was a massive reconfiguration of the region: Paekche and Koguryŏ were destroyed, Silla consolidated control of the Korean peninsula, and Yamato entered a period of rapid centralization, while the Tang retreated. These events demand our attention because they offer insight into the flexibility of East Asian tribute and investiture relations, which shifted but endured throughout this period of extreme volatility.

State violence in early medieval China was characterized by bloody patrimonial politics that contributed to the high degree of political volatility of the period. Like other times in Chinese history, individual monarchs and dynasties came to power through force of arms and kept order by implementing Chinese legal-bureaucratic systems that legitimized violent punishments. The political instability of the early medieval period often can be traced to the informal, patrimonial political ties that intertwined the court, harem, bureaucracy and military. Males and females of the imperial family, eunuchs and generals became involved in the struggle to rule directly or place a puppet on the throne. Winners frequently killed rivals and their adherents. State violence appears to have been most intense during the periods of political division from 220 to 589 and 907 to 960 when “China” was separated into two or more states with relatively frequent internecine conflicts at courts, interstate wars and dynastic transitions via warfare or usurpation. The geographically unified Sui and Tang empires, lasting from 589 to 907, also were disrupted episodically by bloody conflicts at court and rebellions in the provinces.