Battle of Chilcheollyang

The naval Battle of Chilcheollyang took place before dawn on August 27, 1597 (the 15th day of the 7th lunar month 1597) during the Imjin War in Chilcheollyang, which is a narrow strait near Geoje island. It took place during the second invasion of the Japanese. This was the only naval victory for the Japanese during the War.

Prelude
A Japanese double agent was dispatched by the Japanese commanders to bring false information to Admiral Yi and move him into a trap where he could be killed. For a time, the double agent brought what appeared to be important information to the Koreans.

At one point, the agent brought reports of Katō Kiyomasa planning to invade Korea to Gim Eung-seo, a commander of Gyeongsang province. The agent brought the exact place and time of where the Japanese fleet would come. The agent insisted that Admiral Yi go out and intercept the Japanese fleet and destroy it. Gim sent the message to General Gwon Yul, who sent it to Seoul in March 1597. King Seonjo ordered Admiral Yi to attack but Admiral Yi refused, reportedly not trusting a lone letter delivered by an agent and feeling he was unable to prepare for battle in time. Admiral Yi may also have believed that there was a trap at Chilchonryang; the hazardous area contained sharp rocks.

For his refusal, King Seonjo ordered Admiral Yi to be court martialed and stand trial in Seoul. In addition, Won Gyun accused Admiral Yi of drinking and idling. He was spared the death sentence due to his combat record and prime minister Yu Seong-ryong's support. The decision to remove him may have significantly affected further historical events.

Chilcheollyang
Won Gyun replaced Admiral Yi as the naval commander of the entire Korean fleet. Won Gyun decided to attack a large Japanese flotilla of which he did not know the size, strength, or location.

He decided to look for the enemy navy with the entire Korean fleet that Admiral Yi had carefully built and strengthened. Won Gyun left Hansando on August 27, 1597, and soon met a very large enemy fleet near Pusan. Won Gyun was shocked to see the Japanese navy of a size of at least 500 to 1000 ships. Even though his troops were tired, Won Gyun ordered the attack. At the moment of the attack, a commander named Bae Seol quickly ran away with 13 ships under his command knowing the results of the battle ahead. Of note, it was these 13 ships that Admiral Yi would use to defeat the Japanese at Myeongnyang Straits upon his reinstatement. (Commander Bae Seol deserted with his single ship before that battle as well.) The Koreans advanced quickly with barely any strategy when the Japanese returned fire with arquebuses. The Japanese destroyed at least 30 Korean ships by rowing close to the Korean ships and jumping aboard to begin melee combat. The Koreans had no chance to fire with cannons.

Won Gyun retreated back to nearby Gadeok island suffering even more damage to his ships. Apparently, Gadeok island was under Japanese control and when Won Gyun landed with his troops in search of food and supplies, the Japanese commander Chikushi Hirokado of the fort and the island attacked the Koreans and killed 400 Korean marines. Won Gyun quickly retreated and left Gadeok Island.

The Japanese were surprised at this terrible performance of the Korean navy and set out at once to attack the Koreans at night. It was a disaster for the Koreans and the Japanese used their traditional grapple and board attack to overwhelm the Koreans. Admiral Yi had always kept hold of the upper hand by blasting the Japanese from a distance, but Won Gyun had allowed the Japanese to attack the Koreans with swords and spears. After a surprise attack, 200 Panokseons and other Korean ships sank to the bottom of the ocean. Won Gyun was shocked at this attack and retreated quickly again while the Koreans were struggling.

Won Gyun and Yi Eok-gi, another general, struggled ashore at a nearby island with a few survivors. Again, there was another fort with a garrison of Japanese soldiers who rushed outside and killed every single Korean, including Won Gyun and Yi Eok-gi.

Aftermath
The Battle of Chilcheollyang resulted in the destruction of the Korean navy and a huge loss of life. When King Seonjo and the Korean court heard of the battle on July 22, they were left shocked and devastated. They pardoned Admiral Yi (who had spent some time as a common foot soldier under General Gwon Yul), and put him back as the commander of the now small and weak Korean fleet on the same day. With only 200 men, and the 13 ships that Bae Seol had fled with, Admiral Yi then had to fight the Japanese with overwhelming odds against him.

Although he had a disadvantage, Admiral Yi would emerge as a hero and victor at the Battle of Myeongnyang when he destroyed a Japanese fleet of 31 ships with only 13 ships (minus the ship captained by the once again fleeing Bae Seol).

The immediate consequence was a near complete collapse of the allied defenses in southern Korea, as the Japanese forces were now able to surge forward without having to worry about their logistics being destroyed by the Korean navy. Key southern defensive fortresses such as Namwon were left completely exposed.

Within weeks, the Japanese forces took much of Jeolla province and surrounded the fortress of Namwon, and then took it in the ensuing Siege of Namwon.

Source
Annals of Seonjo