Protectorate (imperial China)

Protectorate, also known as Duhu Fu (), was a type of administrative division controlling frontier regions in Imperial China, especially in the Han and Tang dynasties. During the Han and Tang dynasties, a protectorate was the highest government agency in frontier zones and was directly responsible to the central court. The protectorate governor was called "duhu" (literally "capital city protector"), who needed to take charge in military operations when necessary, and provide instructions to minority tribes and small dependent states within the region. Sometimes, a protectorate had subdivisions named commendaries, or Dudu Fu (). The first protectorate was the Protectorate of the Western Regions established in 60 BCE during Emperor Xuan's reign. It controlled the majority of Tarim Basin and some other parts of Central Asia after the Han dynasty defeated Xiongnu. 
Notable protectorates.
Notable protectorates in Chinese history include: