How Did Admiral Yi Sun-sin Win with 13 Ships? Korea's Undefeated Naval Commander

Admiral Yi Sun-sin won the Battle of Myeongnyang in 1597 with only 13 ships against a Japanese fleet of 333 ships, including 133 warships, by fighting in a narrow strait where powerful tidal currents and the terrain cancelled out the enemy's numbers. It was the most famous moment in a remarkable career: during the Imjin War (1592–1598), Yi fought at least 23 naval battles and is credited with winning all of them, although the exact count is debated. What makes his story even more dramatic is that just before Myeongnyang, his own government had arrested, tortured and demoted him.

A late start

Yi Sun-sin was born on 28 April 1545 in Hanseong, today's Seoul. He did not begin as a naval genius. He passed the military service examination in 1576, when he was already in his thirties, and spent years in modest postings on the northern frontier. Shortly before war broke out, he was appointed to command naval forces in the southwest of Korea, and he used that time to prepare.

The Imjin War begins

In 1592 Japan, newly unified under Toyotomi Hideyoshi, invaded Korea with a huge army. On land, Japanese forces advanced rapidly. At sea, the story was very different. Yi's fleet won battle after battle against the Japanese navy, cutting the sea routes that the invaders needed for supplies and reinforcements.

Turtle ships

Yi's most famous weapon was the geobukseon, or turtle ship: a warship with a covered top, often described with spikes to stop boarders, and cannons firing from the sides. Yi designed and built turtle ships for his fleet. Popular history often says he invented the idea of a covered warship, but that specific claim traces back to a 1908 book by a Japanese admiral; the more careful statement is that Yi developed and used turtle ships with great effect.

The turtle ships were only part of the story. Yi's main battle fleet was made of sturdy panokseon warships, and his real advantages were cannons, discipline, local knowledge of the coast and careful planning.

Hansan Island and the "crane wing"

At the Battle of Hansan Island in 1592, Yi lured a Japanese fleet into open water and then wrapped his ships around it in a semicircular formation known as the "crane wing". The Japanese lost 59 ships, 47 destroyed and 12 captured. The victory secured Korea's southern seas and is regarded as one of the most important naval battles of the war.

Arrested by his own side

Success did not protect Yi from politics. In 1597, amid court intrigue, he was relieved of command, imprisoned and tortured. He was spared execution but demoted to the rank of a common soldier.

His replacement, Won Gyun, then led the Korean fleet to a catastrophic defeat at Chilcheollyang, where most of the navy was destroyed. With almost nothing left, the government reinstated Yi. In his reply to the court, he wrote words that every Korean schoolchild knows: he still had twelve warships, and he was still alive. (With his flagship, the fleet numbered thirteen.)

Myeongnyang: 13 against 333

Yi chose his battlefield carefully: the Myeongnyang Strait, a narrow channel off the southwest coast where the tide runs extremely fast and changes direction. In such a narrow space, the Japanese could not bring their numbers to bear, and the current became a weapon.

On the day of the battle, the Japanese fleet of 333 ships, 133 of them warships, came through the strait. Yi's 13 ships held the line, and when the tide turned, it worked against the attackers. The Japanese were forced to retreat. It remains one of the most famous against-the-odds victories in naval history.

"Do not announce my death"

The war ended in 1598 after Hideyoshi's death, as Japanese forces withdrew. At the Battle of Noryang, the last major battle of the war, on 16 December 1598, Yi was hit by a stray bullet. Before he died, he reportedly told his men not to announce his death, so that the battle would not be affected.

Diary and legacy

Yi kept a war diary, the Nanjung Ilgi, recording battles, weather, worries about his mother and frustration with the court. It is part of UNESCO's Memory of the World register. A statue of him stands in central Seoul, and in a 2019 Gallup Korea poll he was named the most respected person in South Korea. Even some of his former enemies admired him; the Japanese admiral Tōgō Heihachirō reportedly rejected a comparison between himself and Yi, regarding Yi as the greater commander.

Learn with Admiral Yi: English phrases

Phrase	Meaning	Example
against the odds	when success seemed very unlikely	They won against the odds.
to turn the tide	to change a situation from losing to winning	One good teacher turned the tide for me.
outnumbered	facing a bigger group	We were outnumbered three to one.
to hold the line	to refuse to give way	The team held the line until the end.
to make the most of	to use something as well as possible	He made the most of the narrow strait.

Try this: Yi turned a weakness into an advantage by choosing the right place to fight. Write three English sentences about a "narrow strait" in your language learning, a situation where you could use your strengths, using "turn the tide" and "make the most of".