Foundation and north–south reunification
Yang Jian founded Sui in 581, reorganizing northern government. Sui conquered Chen in 589 and ended prolonged north–south division. The new court brought together institutions, families and military organizations that had developed in different regions. Sui lasted until 618, with connections between political centers and southern production becoming an important concern of government.
Bringing administration together
Yang Jian replaced Northern Zhou offices with institutions including the Departments of State Affairs, Chancellery and the Inner Secretariat. State Affairs supervised six divisions dealing with appointments, ritual, war, justice, finance and construction. Sui reorganized inherited northern institutions into central offices that Tang later adapted.
New laws were compiled during the Kaihuang reign and revised again in 583, producing a code of twelve sections and five hundred articles known as the Kaihuang Code. It covered general principles, households and marriage, offices, theft, litigation and other matters and reduced some severe punishments. Officials used the code in deciding cases, bringing legal compilation alongside the reorganization of government.
Cities, waterways and mobilization
City construction and canal expansion strengthened connections between political centers and regions. Older waterways were dredged and linked so grain and people could move by water, supporting construction and military operations. Large works required labor and materials. Transport arrangements increased the state’s capacity to mobilize resources while adding responsibilities for local communities.
War and the transition to Tang
Construction and military activity under Emperor Yang continued to mobilize people and resources. Uprisings spread late in Sui, and central rule collapsed in warfare. Tang was founded in 618 and adapted Sui administration and transport. Bureaucratic organization, waterways and experience in north–south integration entered Tang government, leaving lasting effects after Sui’s short rule.