What problems did Taizong face in restoring local government after civil war?

After the civil wars that accompanied the rise of the Tang dynasty, Emperor Taizong faced significant challenges in restoring effective local government:

• Reduced Tax Base: Years of conflict severely depleted the population, leaving Taizong with a tax base reduced by nearly two-thirds compared to the preceding Sui dynasty. This financial strain was exacerbated by a militia system that granted soldiers exemptions from taxes and labor service.1
• Administrative Disruption: It took the majority of Taizong’s reign to restore normal civil administration and establish a unified civil service. By the end of his rule, local administrations had successfully registered only about one-third of the population that had been recorded under the Sui.1
• Social and Political Resistance: Taizong had to contend with the powerful clans of Shandong, who viewed themselves as superior to the imperial house. Additionally, he had to integrate local officials into the broader bureaucracy; many of these positions were initially held by local men or surrendered rebel leaders, and such posts were often viewed by ambitious officials as "exile" from the capital.12

To address these issues, Taizong worked to standardize local administration, expand state schools, and compile national genealogies to assert the primacy of the royal house.1