The Tang Dynasty (618 - 907) had superb military power starting from the reunification of the whole nation at the end of the Sui Dynasty (581 - 618).

The military power was basically founded during the Zhen Guan Reign of Emperor Taizong who was good at using strategies and was strong enough to personally launch expeditions against other ethnic groups. Actually, under the reign of Emperor Taizong, Emperor Gaozong and Wu Zetian, Tang's military track even reached the northern area of the Mongolian Plateau, Gaogouli and Baiji areas. In the 7th century, the territory of the Tang Dynasty even expanded to Central Asia.

Admittedly, the powerful military strength was based on the prosperous social economy and advanced science and technology. Another important factor that contributed to Tang military success was that Tang emperors accepted and appointed many excellent generals from other ethnic minorities, such as Gaogouli, Qidan, Mojie and Tujue. However, in the late Tang Dynasty, the Fubing Military System (in which soldiers did not belong to a fixed commander and supported themselves by farming) was changed into the Mubing System (in which soldiers were recruited by a particular commander and followed him). The latter system made it possible for generals safeguarding the frontiers to easily form strong military forces against the court.

In this way, the An Shi Rebellion broke out, which severely attacked the Tang military power. Eventually, under pressure from domestic separatist forces and invasion by outer ethnic minorities, the Tang military force gradually withered and died.