The two characters of jimi first meant a horse's halter and an ox's tether, and came to mean holding on without pulling tight. Applied to the frontier, it means that the court did not run the borderlands directly nor give them up, but invested the local chiefs with titles and let them govern their own people.
The Western Han set up the Protectorate of the Western Regions, holding the oasis states through investiture and military protection, a precedent for this kind of indirect rule.
In 630, the fourth year of Zhenguan, after the Tang defeated the Eastern Turks, it began creating loose-rein prefectures headed by hereditary tribal chiefs as commissioners and prefects, and the system took formal shape.
Under the Qing Yongzheng Emperor the court carried out large-scale reforms, replacing the indirect rule of hereditary native chieftains with direct administration by appointed officials.
Loose-Rein Rule is the class in the chapter on Strategies on how the borderlands were governed. It covers the indirect rule that central dynasties exercised over tribal areas on the frontier: tribal chiefs were invested with titles and allowed to hold hereditary posts as military commissioners and prefects, with their self-rule kept. The Western Han set up the Protectorate of the Western Regions as the first step, the Tang loose-rein prefectures took shape, and after the Yongzheng-era reform of replacing native chiefs with appointed officials the areas were governed directly.
