Taejo of Goryeo
After the fall of Silla, Taejo of Goryeo established the capital of his kingdom in Kaesŏng, now just north of the Demilitarized Zone. During the Mongol invasions of Korea in the 12th century, the seat of government briefly shifted to Ganghwa Island, now just south of the DMZ in Incheon metropolitan city, where the Mongol naval attacks were repelled for about a decade before the king voluntarily surrendered to stop the carnage the Mongols committed in the peninsula, in order to lure the king out.