Yi Sunsin (1545-1598) was a Korean military strategist and naval hero. His victories during the Japanese invasions of Korea are remembered by modern Koreans as among the most heroic feats in their history.
Yi Sunsin was born in Seoul on April 18, 1545, the son of a gentry family of moderate means. Although in his early education he aimed for a civil career, he decided, when 21 years old, to become a military officer. After passing the military examinations in 1576, he served in a variety of posts, both on the northern frontier against the Jürchen tribesmen and on the southern coast as the commander of a small naval station. In all his assignments he demonstrated his competence and courage and also a narrow insistence on doing everything according to regulations. His attention to correct procedure was at the root of his later organizational successes, but it also marked him as a man difficult to get along with.
In his early career Yi was rather unpopular, and his successes earned him more jealousy than praise. In time, however, he began to attract attention in high places, and from 1589, when he served on the staff of the Cho‧lla provincial military inspector, his reputation rose steadily. In 1591 he was appointed, over many senior officers, commander of the Left Cho‧lla Fleet (Korea's two southernmost provinces, Kyo‧ngsang on the east and Cho‧lla on the west, were each divided into Left and Right naval districts).
When Yi reached his post, in the town now known as Yo‧su, the Japanese invasion was still 14 months away. The Korean court had had hints of the Japanese plans as early as 1590, but it was deeply divided over the meaning of the threat. The Japanese dictator Toyotomi Hideyoshi had said plainly that he intended to invade Ming China and required transit through Korea, but few believed he would attempt a land invasion, and even these had little idea how massive it would be.
Yi, however, believed war would come and began preparations from his arrival at Yo‧su. He strengthened the fortifications and enforced discipline with an awesome sternness. But most of his attention was given to the development of the famous "turtle ships." These vessels had a curved covering deck which resembled a turtle carapace. The deck and sides were ironclad and bristled with spikes to prevent boarding. On the prow was a fierce-looking dragon head in which was mounted a medium gun; along the sides were 12 gunports with heavy pieces which could fire missiles, spears, or buckshot. On the high seas the ships moved by sail power; in action the sails and masts were removed and oars were used. Vessels resembling the turtle ships had been known earlier in both China and Korea, but it was Yi who perfected the design and, more importantly, developed the tactics by which they could be most effective. He used the turtle ships as attack vessels; they would move directly into the enemy force and disrupt it and then go after the bigger ships, either ramming them or broadsiding them with the heavy cannons.
The Japanese invasion force landed at Pusan on May 25, 1592. The first Korean naval encounter proved disastrous: under the timid commander of the Right Kyo‧ngsang Fleet, Wo‧n Kyun, nearly the whole Kyo‧ngsang fleet was lost or scuttled. Yi boldly decided not to wait for an attack but to go on the offensive immediately. On June 13 he left Yo‧su with a fleet of 85 ships; 24 of these were armed warships (not including the turtle ships, which were not yet ready), the rest communication and supply ships. When he returned a week later, he could claim a total of 42 enemy ships destroyed or taken, all but 2 of these being large or medium vessels. He himself had suffered no losses.
In the months afterward Yi led three more expeditions from Yo‧su, now adding the powerful turtle ships to his squadron. These proved spectacularly successful in a major battle off Hansan Island on August 14, when Yi met a force of 73 Japanese ships and sank or took 59 of them; his own losses were minimal. Four such expeditions made in the summer and fall netted 375 Japanese ships.
The reasons for Yi's conspicuous success lay in his general aggressiveness, his total knowledge of the notoriously tricky Korean coastal tides, and his mastery of engagement tactics, whereby he was able to lure the enemy out to the open sea, where he could maneuver with greater freedom. The Japanese later learned to avoid these encounters, but at the cost of keeping themselves bottled up in the coves and inlets.
The strategic effect of Yi's early victories was considerable. By keeping the enemy from the Cho‧lla coasts, he ensured the safety of his own bases. He made the Japanese land occupation of Cho‧lla Province impossible, thus retaining its major rice and manpower resources. Finally, he kept the Japanese navy completely away from the west coast of the peninsula and away from the major cities of the north, thus weakening the Japanese land positions near P'yo‧ngyang and contributing to the eventual loss of the positions.
In mid-1593 the war had reached a stalemate: the Japanese had been forced back to their coastal strongholds near Pusan, where the Koreans and their Chinese allies had the power to hold them but were unable to expel them. At this juncture peace talks began between the Chinese and Japanese generals. The Koreans did not join these talks and, in fact, fought a limited number of battles during 1593 and 1594, but in general they were forced to go along with the truce. Yi moved his headquarters eastward to Hansan Island—closer to the main Japanese base at Pusan—and assumed the post of commander of the Unified Triprovincial Fleet, a title created especially for him which in effect gave him command of the entire Korean navy (July 1593). But this period was for him one of enforced idleness, frustrating and unpleasant.
When the peace talks collapsed in 1596, Toyotomi Hideyoshi began to ready a second invasion. Having been unable to eliminate Yi in combat, the Japanese resorted now to intrigue and exploited Korean factionalism and their own. On the one hand, Yi's steady successes had reaped the jealousy of his court enemies, who backed the incompetent Wo‧n Kyun. On the other, there was a deep rift between the two principal Japanese generals, Konishi Yukinaga and Kato Kiyomasa. Through a double agent, Korean officials were persuaded that Konishi wanted to kill Kato and, to accomplish this, would tell Yi the date and place of Kato's crossing from Japan. Yi recognized the obvious trap and refused to obey the court's instructions to join the plot. For this insubordination his enemies had him arrested and brought to Seoul. Here he was tried and sentenced to death, but his supporters were able to have this commuted to banishment in custody of the army. Stripped of his rank and titles, Yi joined the headquarters of the Cho‧lla army on July 17, 1597.
Yi's vindication was not long in coming. No sooner had Wo‧n Kyun assumed Yi's former commands than he led over 200 ships into a disastrous defeat (Aug. 27, 1597). With Wo‧n Kyun dead and only a handful of ships left and the base at Hansan Island untenable, the survivors burned their naval stores and retreated to the Cho‧lla coast. The humiliated court was now forced to return command to Yi. Re-appointed on September 13, he reached his ragged fleet 2 weeks later to find he had only 12 ships, none of them turtle ships, and only a handful of demoralized men. He had no supplies, and his base at Yo‧su was unusable. Moreover, the Japanese were now sweeping through the major inland Cho‧lla cities and massing their ships for a decisive blow at the remaining Korean naval force.
But Yi, combining his meager resources with courage and a thorough knowledge of his native waters, produced his greatest victory, the battle of Myo‧ngnyang (Oct. 26. 1597). Allowing his tiny group to be sighted by the Japanese force of 133 ships, he lured them into the Myo‧ngnyang Strait, between the mainland and the large island of Chindo. While the narrow space provided sufficient maneuverability for Yi's 12 ships, most of the enemy vessels were put out of the battle for lack of room—"one man on a narrow mountain path can terrorize a thousand," as Yi remarked in his diary. After the tide shifted in his favor, he pursued the enemy, and when the day was over, 31 of the retreating Japanese ships had been sunk while Yi had lost none.
The Japanese advance collapsed, and by the end of 1597 they were forced once more to cling to their narrow strip of coastline. Chinese reinforcements streamed into Korea, including a naval force under the admiral Ch'en Lin, who joined Yi at his southern headquarters in August 1598. The two began an uneasy but fruitful relationship. To his other skills Yi now added those of the diplomat in order to contain his vain and temperamental Chinese colleague.
In October 1598, after a Chinese offensive against the coastal strongholds had failed and it looked as if another long standoff was in prospect, Toyotomi Hideyoshi suddenly died, leaving behind a deathbed order to bring all troops home from Korea. Most of the Japanese were able to buy off their besiegers and evacuate their fortifications without difficulty, but Konishi Yukinaga, held in his bastion near Sunch'on, found himself opposed by a strong Sino-Korean fleet and an unbribable Yi. On December 14-15 a massive Japanese fleet came to Konishi's rescue. The furious fight that followed, known as the battle of Noryang, was the bloodiest of the war. Konishi escaped, but the Japanese lost some 200 ships and thousands of men. However, the Koreans and Chinese sustained heavy casualties. The greatest loss was Yi himself, hit in the neck by a bullet as he stood beside his signalman at the height of the battle. His last order was to keep his death a secret until the battle was over, lest the news adversely affect the outcome.
Yi is Korea's greatest hero and one of the outstanding naval commanders of world history. His battles, well documented in his diary and reports, bear careful study by modern naval historians, and his courage and patriotism are still models for modern Koreans of all persuasions, who find in him a powerful symbol of national resistance against foreign powers, particularly the Japanese.
There is no biography of Yi Sunsin in English. Some details of his life and achievements can be found in standard survey histories, such as Takashi Hatada, A History of Korea, translated and edited by Warren W. Smith and Benjamin H. Hazard (1969); and Woo-keun Han, The History of Korea, translated by Kyung-sik Lee and edited by Grafton Mintz (1970).
Park, Yune-hee, Admiral Yi Sun-shin and his turtleboat armada, Seoul, Korea: Hanjin Pub. Co., 1978.