China, a History

The 7th century and first half of the 8th century is generally considered the zenith era of the Tang Dynasty. Emperor Tang Xuanzong (r. 712–756) brought the Middle Kingdom to its golden age while the Silk Road thrived, with sway over Indochina in the south, and to the west Tang China was master of the Pamirs (modern-day Tajikistan) and protector of Kashmir bordering Persia. Some of the major kingdoms paying tribute to the Tang Dynasty included Kashmir, Neparo (Nepal), Japan, Korea, Vietnam, and over nine kingdoms located in Amu Darya and Syr Darya valley. Nomadic kingdoms addressed the Emperor of Tang China respectfully as Tian Kehan. Under Emperor Xuanzong, several military provinces were established on China's frontiers from Sichuan to Manchuria, as the military governors of these were given a great deal of autonomy to handle local crises without waiting for central admission. By the year 737, Emperor Xuanzong discarded the policy of conscripting soldiers that were replaced every three years, replacing them with long-service soldiers who were more battle-hardened and efficient. It was more economically feasible as well, since training new recruits and sending them out to the frontier every three years drained the treasury. By the year 742 the total number of enlisted troops in the Tang armies had risen to about 500,000 men.