Yi Sun-sin

Yi Sun-sin was born on April 28, 1545, in Hanseongbu, the capital district of Joseon Korea, in the neighborhood of Geoncheon-dong (in present-day Seoul) ^[1]. His family belonged to the Deoksu Yi clan, a yangban lineage of scholars and officials whose fortunes had declined by the time of his birth. His grandfather had been caught up in the political purges that swept the court earlier in the century, and the family lived modestly, later moving to Asan in Chungcheong Province, the hometown of his mother's family, where the boy spent much of his youth ^[2].

As a child of the scholar class, Yi received a classical Confucian education and was expected to sit the civil service examinations. Instead, in his twenties he turned toward the military track, a less prestigious path in a state that prized civil office above soldiering. He trained in archery, horsemanship, and the military classics. His first attempt at the military examination, in 1572, ended in failure when he fell from his horse and broke his leg; the often repeated account records that he bound the injury with a willow branch and tried to continue ^[1].

He passed the military examination in 1576, at the age of 31, older than most successful candidates. His first postings sent him to remote frontier garrisons in the north, where Joseon forces skirmished with Jurchen raiders along the Tumen River. There he earned a reputation for discipline and honesty, qualities that did not always endear him to superiors, and his early career included demotions and periods out of favor as well as steady, unglamorous service ^[2].

For most of the 1580s Yi Sun-sin was an obscure officer. He served on the northern frontier, where he fought Jurchen incursions, and at one point was stripped of rank after a defeat for which his commanding officer assigned him blame; he served as a common soldier before regaining office ^[2]. This pattern, honorable service followed by political setback, recurred throughout his life and shaped his reputation as a man who answered to duty rather than to faction.

His fortunes changed through the patronage of Yu Seong-nyong, a childhood acquaintance who had risen to high civil office. As tensions with Japan grew in the early 1590s, Yu recommended Yi for naval command, and in 1591 the court appointed him Left Naval Commander of Jeolla Province, responsible for the fleet guarding Korea's southwestern coast ^[3]. It was a dramatic promotion for an officer with no prior naval experience of consequence.

Yi used the year before the war to prepare. He drilled crews, stockpiled provisions, repaired fortifications, and oversaw shipbuilding at his headquarters at Yeosu. Under his direction the shipwright Na Dae-yong worked on the geobukseon, the so-called turtle ship, a heavily protected warship with a covered deck studded with iron spikes and cannon firing from all sides ^[4]. The vessel drew on earlier Korean designs but was revived and refined under Yi's command, and the first of the new turtle ships was completed on the eve of the Japanese invasion ^[4].

In May 1592 the armies of the Japanese regent Toyotomi Hideyoshi landed at Busan and swept north, taking Hanseong within weeks. On land Joseon's defenses collapsed, but at sea the war took a different course, and it is here that any account of Yi Sun-sin achievements must begin. Sailing east from Jeolla waters, Yi won his first action at Okpo in June 1592, destroying dozens of Japanese vessels without losing a ship of his own ^[3]. Victories followed in rapid succession at Sacheon, where the turtle ship first saw combat, and at Dangpo and Danghangpo ^[4].

The decisive engagement of that first campaign season came at Hansando in August 1592. Luring the Japanese fleet into open water off Hansan Island, Yi deployed his ships in the crane wing formation, an enveloping crescent that brought massed cannon fire to bear on the enemy from multiple directions. Japanese losses ran to dozens of warships, and the battle broke Japanese hopes of controlling the sea lanes along Korea's southern coast ^[3]. Korean panokseon warships, sturdy flat-bottomed vessels built to carry heavy guns, consistently outranged Japanese ships, whose crews favored closing and boarding. Yi's tactics exploited that difference relentlessly, keeping his fleet at distance and using geography, tides, and narrow channels to fight on his own terms ^[5].

The strategic effect was larger than any single battle. Hideyoshi's plan required moving troops, rice, and munitions by sea to armies advancing toward China. Yi's fleet, later joined by Ming Chinese naval forces, made the western sea route unusable, starving the Japanese advance of supply and helping to stall the invasion far short of its goals ^[5]. In 1593 the court created the new post of naval commander of the three southern provinces (samdo sugun tongjesa) and gave it to Yi, uniting Korea's southern fleets under one command for the first time ^[3].

Success bred enemies. Court factions distrusted Yi, and rival commander Won Gyun worked against him. In 1597, during the renewed Japanese offensive known in Korea as the Jeongyu invasion, a Japanese double agent fed the Joseon court intelligence designed to lure the fleet into a trap. Yi judged the reported enemy movement to be a ruse and declined to sail into waters he considered fatal. For this he was arrested, taken to the capital in chains, interrogated under torture, and nearly executed; only the intervention of senior officials reduced his sentence to demotion, and he was ordered to serve as a common soldier under another general ^[2].

Command of the combined fleet passed to Won Gyun, who in July 1597 led it to catastrophe at Chilcheollyang, the only major Korean naval defeat of the war. Nearly the entire fleet was destroyed and Won Gyun was killed ^[3]. With the sea suddenly open to Japan, the desperate court restored Yi to command. He found, by his own count recorded in his dispatches, only a handful of surviving warships, conventionally numbered at twelve, to which one more was added ^[6]. Advised to abandon the sea entirely, he replied to the throne that he still had twelve ships and that he remained alive, and that the enemy would therefore not find the sea safe ^[6].

On October 26, 1597, Yi met the Japanese fleet in the Myeongnyang Strait, a narrow channel off Jindo Island where fierce tidal currents reverse direction through the day. Anchoring his small squadron where the strait constricted, he forced the far larger Japanese force, recorded in Korean sources as numbering in the hundreds of vessels, to attack piecemeal into the bottleneck. Korean cannon fire and the turning tide wrecked the leading Japanese ships, and the attackers withdrew with heavy losses; some thirty or more of their warships were destroyed while Yi lost none ^[3]. Myeongnyang restored Korean control of the western approaches and is remembered as one of the most improbable victories in naval history ^[5].

Yi married a daughter of the Onyang Bang family in 1565, and the couple had three sons and a daughter; he also had children by a concubine, as was customary among yangban men of his era ^[2]. Family duty weighed on him throughout the war. His diary records his anguish in 1597 when his elderly mother died while he was returning from imprisonment, and later that year his youngest son, Yi Myeon, was killed by Japanese soldiers in a raid near the family home at Asan, a loss that left some of the most grief-stricken passages in his writings ^[6].

That diary, the Nanjung ilgi (War Diary), is central to how posterity knows the man. Kept almost daily from 1592 until days before his death, it mixes weather reports, fleet administration, and tactical notes with candid remarks on illness, insomnia, worry for his family, and frustration with colleagues and the court. Together with his official dispatches to the throne, the Imjin jangcho, it forms one of the most detailed first-person records left by any commander of the early modern world, and UNESCO inscribed the diary in its Memory of the World register in 2013 ^[7].

Contemporaries described a stern, upright, and privately reflective man. He wrote poetry, including a famous sijo verse composed on night watch at Hansan Island, and held to Confucian ideals of loyalty and filial piety even when the state he served treated him unjustly ^[6]. He was wounded in action more than once, including a gunshot wound to the shoulder at Sacheon in 1592 that troubled him for years ^[2].

After Myeongnyang, Yi rebuilt the fleet almost from nothing. He moved his base to Gogeumdo, gathered refugees, revived shipyards, and secured provisions, so that by 1598 he again commanded a substantial force operating alongside a Ming Chinese fleet under Admiral Chen Lin ^[3]. Relations with the Ming commander began uneasily, but Yi's tact and battlefield results won Chen Lin's respect, and the allied fleets operated jointly through the final campaign ^[5].

Toyotomi Hideyoshi died in September 1598, and the Japanese armies in Korea were ordered home. Yi and Chen Lin moved to block the evacuation of the Japanese garrison at Suncheon, and when a large relief fleet came to extract it, the allies attacked in the strait of Noryang before dawn on December 16, 1598. In hours of close fighting, the allied fleets destroyed a large part of the Japanese force ^[3].

Near the end of the battle Yi was struck by a musket ball. According to the accounts passed down by his family and recorded in early sources, he ordered those beside him to conceal his death until the fighting ended, saying that the battle was at its height and his death must not be announced ^[1]. He died on his flagship at the age of 53, in the last significant engagement of the war he had done so much to decide. The court posthumously showered him with honors, and in 1643 he received the posthumous title Chungmugong, Duke of Loyal Valor ^[2].

Anyone asking who was Yi Sun-sin encounters a rare figure: a commander credited with victory in every naval battle he fought, conventionally counted at more than twenty engagements without a defeat ^[3]. Naval historians have ranked him among the greatest admirals of any nation, and admirers have long noted the praise attributed to officers of the Imperial Japanese Navy, whose own tradition studied his campaigns in the era of Admiral Togo ^[5]. His combination of gunnery-based tactics, use of tide and terrain, logistics, and intelligence gathering is still taught in staff colleges.

In Korea his memory is inseparable from national identity. The giant statue of Yi Sun-sin erected in 1968 stands over Gwanghwamun Square in central Seoul, sword in hand, facing the direction from which invasion once came ^[8]. His shrine at Hyeonchungsa in Asan draws steady visitors, replica turtle ships float in southern harbors, his portrait appeared on the 100 won coin, and the destroyers of a modern Republic of Korea Navy class bear his name. The 2014 film about Myeongnyang, released internationally as The Admiral: Roaring Currents, became the highest grossing film in South Korean history at the time ^[8].

Beyond monuments, the basic Yi Sun-sin facts retain their force: a provincial officer, twice broken in rank and once tortured by his own government, who kept an unbeaten fleet at sea for six years and helped save his country from conquest. His diary preserves the private cost of that achievement, which is one reason a Yi Sun-sin biography reads less like a legend than like the record of a conscientious man asked to do the impossible, who did it, and who did not live to see the peace ^[6][7].