Jingwan defence system
King Sejo set up the jingwan system, grouping the troops of nearby counties under a key garrison town in each province for self-defence. The central army was reorganised into the Five Guards.
Military service in Joseon was in principle owed by all commoner men aged 16 to 60, with serving officials and students exempt. Those liable either served as active soldiers or became “supporters” (boin) who paid for them (the bo system, 1464). The central army, the Five Guards (Owi), protected the palaces and capital; in the provinces regular soldiers served in army and navy garrisons as yeongjingun. Clerks, technical specialists, low-status commoners and slaves were enrolled in the japsaekgun, a reserve that kept to its livelihood and was mobilised only in emergencies.
In 1457 Sejo placed an army headquarters in each province and grouped the troops of surrounding counties under major garrisons (geojin) at strategic points. As a local defence system in which each district defended itself, one jingwan could hold even if another fell, but its forces were too scattered to stop a large enemy.
In the 16th century, as the practice of collecting cloth in lieu of service spread and the number of soldiers fell, the system shifted around the time of the Eulmyo Incident (1555) to jeseung bangnyak, under which troops from many counties were gathered at one point in an emergency under a commander sent from the capital. When Sin Rip was defeated at Tangeumdae early in the Imjin War, the weakness of an undefended rear became clear, and on Ryu Seong-ryong’s advice the jingwan system was restored and the sogogun formed.
