Jeongjong Organizes the Gwanggun

Jeongjong, third king of Goryeo, raised a 300,000-strong reserve army, the Gwanggun, against the Khitans and set up the Gwanggunsa to command it.

Jeongjong took the throne after crushing Wang Gyu’s revolt (945) with troops from Wang Sik-ryeom of the Western Capital. Seeking to escape the grip of the Gaegyeong lords, he planned to move the capital to Seogyeong, building a royal fortress there and resettling people, but the works caused much resentment and the plan died with him in 949.

With the Khitans, destroyers of Balhae, now a northern threat, in 947 he selected 300,000 men as the Gwanggun and created the Gwanggunsa in Gaegyeong to command them. It bound the regional lords’ troops together in the state’s name and is thought to have formed the basis of the later provincial army (juhyeongun). An extension of the northern policy wary of the Khitans since Taejo, it came half a century before the first Khitan invasion of 993.