Battle of Yonan

On October 3, 1592, about 1,000 vanguard members of Kuroda Nagamasa, the commander of the 3rd Division of the Japanese Army, approached the Yonan Fortress. Some offered to abandon the fortress to Yi Jeong-am based on the Japanese military's vigor, but Yi refused.^[8]

The Japanese army surrounded the fortress and sent a letter to the envoy, which urged him to surrender. Yi Jeong-am wrote to the envoy, saying, "You fight with soldiers, but we fight with righteousness." The Japanese troops who surrounded the fortress began to climb the fortress using ladders. They also came up by connecting wooden plates to the fortress. The righteous army shot arrows and rolled stones to defeat the Japanese soldiers who were scaling the walls.^[9] On that afternoon, a Japanese general approached the fortress riding a white horse holding a white flag, Jang Eung-gi shot a bow to hit his chest, and quickly opened the gate and cut off his head, raising the morale of the righteous army.^[10]

On October 4, the Japanese army launched a full-fledged assault with arquebuses, and Yi Jeong-am allowed the defending army to shoot arrows only at the Japanese soldier climbing rampart, preparing for a long-term war and used boiling water to defend the fortress.^[8] Japanese soldiers climbed the fortress using ladders and wooden plates again. Some had already climbed to the fortress. Yi Dae-chun, the chief of the west gate, cut down those who climbed the fortress and fired iron arrows to drop the wooden plates. As the large and heavy plates fell, all the Japanese soldiers below were crushed to death.^[9] The Japanese forces built a high attic on Namsan Mountain and opened a hole in the wall of the board, looked down, and fired guns.^[8] In response, in the fortress, piles of earth walls were built to block it.^[11] On that night, the Japanese attacked the fortress with flaming arrows at the west gate, but the fire was extinguished due to the change of wind due to the headwind.^[2] A soldier who guarded the rampart as the enemy sneaked up to the western rampart under the cover of the fog at night surrounded them with torches and burned more than 40 soldiers.^[11]

On October 5, Japanese commander Kuroda Nagamasa personally led and commanded 5,000 soldiers. The righteous army resisted the Japanese by throwing all weapons, but the Joseon righteous army and people, who were on the defensive, were inferior in number. When the fortress was on the verge of being destroyed, Yi Jeong-am piled firewood and sat on top of it and called his son, Yi Jun, to say this: "If this fortress falls, set it on fire. I would rather burn myself here than be insulted by the Japanese."^[2]

Also, Kim Hyo-sun, who was held captive by the Japanese military amid the war, escaped and ran to Yonan Fortress, bringing with him a message that, "The enemy will withdraw if we hold out until tomorrow morning.".^[9] With the encouragement of the commander and the message of their prisoner of war who escaped from the enemy camp, the morale of the soldiers of Joseon was renewed.

On the night of October 6, Jeon Hyeon-ryong and Jo Sin-ok snuck out of the gate, took the straws to the Japanese camp and set it on fire. As the flames soared, the Japanese scattered.^[9] Yi Dae-chun threw burning straw on the Japanese soldiers climbing up the wall. When the morning dawned, the Japanese army eventually gave up on the Yonan fortress and retreated. Yi Jeong-am formed a chase team led by Yi Dae-chun to raid the rear of the Japanese army. They captured about 90 horses and cows, and 130 bushels of rice and the battle ended.^[1]

The Japanese military suffered numerous casualties and losses in the armed forces. After losing the battle, Kuroda Nagamasa's Third Army changed its operation from trying to take control of the entire Hwanghae Province to guarding areas near major supply routes from Hanyang to Pyongyang.^[5] As a result, Joseon was able to protect Yeongbaek Plain, a granary in the Hwanghae, as well as secure transportation routes from Jeolla Province to Uiju.^[5] In addition, the wandering people of about 10 towns north of the Yonan were able to return to their homes, and the fleeing leaders were able to return to the main town.^[3]

Without posting a lengthy report, Yi Jeong-am only sent eight letters to the government, saying, "The enemy surrounded the fortress on someday and retreated on someday." ("某日圍城, 某日解去")^[3] However, as the fact that they fought against about 3,000 became known soon, Yi Jeong-am was appointed as a governor of Jeolla Province, and Jang Eung-gi, Jo Jong-nam, Jo Seo-ryong, and Bong Yo-sin, who participated in the battle together, were also rewarded with government posts.^[8]