Yi Sun-sin

Yi Sun-sin was a Korean admiral of the Joseon dynasty who commanded the navy against the Japanese invasions of 1592 to 1598, known in Korea as the Imjin War. By cutting the sea routes on which the invading armies depended, he did more than any other commander to defeat the invasions, and he died in the war's last great battle. He is remembered in Korea as its greatest national hero, and naval historians rank him among the finest admirals of any age.

Yi was born on 28 April 1545 in Hanseong, the Joseon capital, today's Seoul, into a family of the yangban, the scholar-official class. His grandfather had fallen victim to a court purge and his father never held office, so the family carried little influence. As a boy he moved with his family to Asan, in the south-west, where he later married. Rather than the civil service examinations expected of his class, he trained for the military examination. At his first attempt in 1572 he fell from his horse and broke a leg; he passed in 1576, at the age of 31, unusually old for a junior officer.

He spent his early service on the northern frontier in Hamgyeong province, fighting raids by the Jurchen, the people whose descendants would later found the Qing dynasty. He won a reputation for competence and honesty, but also made enemies. In 1587, after a Jurchen attack on a post under his command, a superior blamed him for the losses; he was stripped of rank and served for a time as a common soldier before being restored. His career owed much to the patronage of Yu Seong-ryong, a senior minister who had known him since youth.

In 1591, with the help of Yu, Yi was promoted rapidly to command the Left Naval District of Jeolla province, based at Yeosu on the south coast. He had little naval experience, but he took the threat from Japan seriously. The warlord Toyotomi Hideyoshi had just unified Japan after more than a century of civil war and openly planned to conquer China, with Korea as his road. While much of the Joseon court discounted the danger, Yi drilled his crews, stockpiled supplies, repaired fortifications and improved his ships.

The best known of these was the geobukseon, or turtle ship. Turtle ships are mentioned in Korean records from the early fifteenth century, so Yi did not invent the type, but he revived and redesigned it. It was built on the hull of the panokseon, the sturdy Korean warship of the period, with a covered deck, probably fitted with spikes to stop boarders, and cannon firing through ports on every side. Whether the cover was plated with iron is still debated. Only a few were ever built; the bulk of Yi's fleet was always panokseon, whose heavy guns gave Korean ships a decisive advantage over Japanese vessels designed for boarding.

Japanese armies landed at Busan in May 1592 and took Seoul within three weeks, as King Seonjo fled north. On land the Korean defence collapsed. At sea, Yi struck at once. In a series of actions beginning at Okpo in June, he destroyed dozens of Japanese ships without losing any of his own, and in one action at Sacheon he was wounded in the shoulder by a musket ball. On 14 August 1592, at Hansan Island, he lured a large Japanese squadron out of a narrow strait into open water and enveloped it in a "crane wing" formation, sinking or capturing around 59 ships. After this defeat Hideyoshi ordered his fleet to avoid battle with the Koreans.

These victories mattered far beyond the ships sunk. The Japanese plan relied on moving troops and supplies by sea along the west coast of Korea. With that route closed, the armies in the north were starved of reinforcements, while Korean guerrilla forces and a large relief army from Ming China pushed them back. In 1593 Yi was named Naval Commander of the Three Provinces, giving him command of all the southern fleets.

Years of inconclusive negotiation followed, and the court was split by bitter factional rivalries. In early 1597 Yi refused an order to attack a Japanese fleet on the strength of intelligence he believed to be a trap. His rivals, among them the admiral Won Gyun, used the refusal against him. He was arrested, taken to Seoul, interrogated under torture and nearly executed, before being demoted again to the ranks. His mother died shortly after his release, while he was travelling south to serve in the ranks.

Won Gyun replaced him, and in August 1597, when the Japanese renewed the invasion, he led the Korean fleet into a disastrous defeat at Chilcheollyang, where he was killed and almost the whole navy was destroyed. The king hurriedly reappointed Yi, who found only about 13 warships left. Ordered to abandon the sea and join the army, he refused. On 26 October 1597 he met a Japanese fleet of more than 130 warships in the Myeongnyang Strait, a narrow channel off the south-western coast with fierce tidal currents. Using the narrows to stop the enemy deploying its numbers, and timing the battle to the turn of the tide, he sank or disabled some 30 Japanese ships and forced the rest to withdraw. The exact numbers are uncertain, but the battle is counted among the most remarkable victories against odds in naval history.

Hideyoshi died in September 1598, and the Japanese commanders began to withdraw their armies from Korea. Yi, now cooperating with a Ming fleet under the admiral Chen Lin, set out to intercept them. On the night of 15 to 16 December 1598, at the Battle of Noryang, the allied fleets attacked a large Japanese force trying to break through to relieve its comrades. In the fighting, Yi was struck by a bullet. According to the traditional account, he told those around him to conceal his death so that the battle would not be lost, and his nephew kept the drums beating in his place. The battle ended in an allied victory, and the war ended with it.

Yi was given the posthumous title Chungmugong, Lord of Loyalty and Martial Valour. He left a war diary, the Nanjung Ilgi, a candid daily record of battles, logistics, illness, grief and frustration with the court, now listed on UNESCO's Memory of the World register. Historians generally credit him with at least 23 engagements without a defeat, though the exact count depends on how actions are defined.

His reputation grew over the following centuries, and in the twentieth century, especially under Japanese colonial rule and after independence, he became a central symbol of Korean resistance and patriotism. His statue stands on Gwanghwamun Square in Seoul, and he appears on Korean coins and banknotes, in films and in countless school lessons. Modern historians of the war in Korea and abroad also stress the wider picture, in which Ming armies, Korean irregular forces and the logistical limits of the invaders all contributed to Japan's defeat, but Yi's control of the sea remains central to every account.

Our maps for the 1590s show the Joseon kingdom under attack from Hideyoshi's Japan, with the Ming empire to the north. The wider story is told in the History of South Korea.