The military system during the middle period of the Silla dynasty was divided into wartime and peacetime structures; with the wartime structure divided into central and regional armies. On the other hand, these central and regional armies, which were under separate control under the peacetime structure, were re-organized in the wartime structure. Military organizations such as the 6-jeong, 9-seodang, 10-jeong, 5-juseo, 3-mudang, and Gyegeumdang, all of which are referred to in the Jikgwanji Mugwangjo section of the Samguksagi, were formed under the wartime structure. The wartime structure was formed as part of the reorganization of the military system which occurred during the process of establishing an absolute monarchy during the reigns of King Munmu and King Sinmun in the latter period of the 7th century.
Under the peacetime structure, the central army was composed of the Mugwan and soldiers drafted from the regular class. The Mugwan were usually noble class members from such classes as the 4, 5, and 6 dupum and Jingol classes who were either recommended for the post, got in through Muneum connections-, or after having passed an archery test. These Mugwan became the basic foundation of the central army. The Mugwan were responsible for protecting the king, the security of the capital area, the defense of borders, and controlling regular soldiers. It is estimated that there were 2,368 Mugwan in the central army, consisting of 2,188 within the wartime structure and 180 from the Siwibu.
Under the peacetime structure the regional army was established nationwide, with units in the capital area (wang gung), nine provinces (ju), five major cities, 115 counties (gun), and 296 villages (hyeon). The governors (Dodok) of the nine provinces eventually seized military power and assumed direct control of the Sajageumdang and Bigeumdang units located within each province, as well as of the Beopdang corps. These Dodok were able to use this military power to maintain security in their respective provinces. This power was also used to attempt coups against the central government. During the latter period of the Silla dynasty the literati class began to be appointed as regional governors, which signaled the decline of regional armies and the emergence of local civilian power.