Yi Sun-Sin: The Greatest Admiral of all Time?

We explore a towering figure of naval warfare and ask whether he stands atop all of history's admirals.  

Transcript

The Greatest Admiral of All Time?

December 2025

“Even Yi Sun-Shin’s success in battle depended as much upon his courage as his brilliance as a strategist. It is thus his humanity, as well as his genius, that is worthy of our attention.”

Marc Jason Gilbert

“My life is simple, my food is plain, and my quarters are uncluttered. In all things, I have sought clarity. I face the troubles and problems of life and death willingly. Virtue, integrity, and courage are my priorities. I can be approached, but never pushed; befriended but never coerced; killed but never shamed.”

Yi Sun-Sin

What is it about land vs sea?  From Salamis to Lepanto.  From Trafalgar to the Midway sea battles have been critical for the success of war.  Even in a Civil War such as that fought on the North American Continent, naval power was a factor with the first fight between ironclads, the Union blockades, driving up the Mississippi, and Farragut’s “Damn the Torpedoes, Full Speed Ahead!”

The reason most history buffs can recite long lists of 20-30 generals but might struggle with naming five admirals is the simple fact that we are land creatures.  Ultimately, wars of conquest or defense do come down to numerous land battles.  It took Caesar ten years and numerous large-scale set-piece battles to conquer Gaul.  This meant Caesar had several chances to burnish his reputation and many battles to study.   The greatest admirals, such as Don John of Austria, only had Lepanto. This crucial battle checked Ottoman power in the Mediterranean, but it did not yield a long list of accomplishments.   

And another factor.  Even after Rome suffered several defeats in set-piece battles against Hannibal, including a decisive defeat at Cannae, it fielded newly trained legions in less than one year.  It is easier to train men and equip them with Pilas, swords, and helmets than it is to build a fleet of 200 galleys. When the Japanese lost four heavy aircraft carriers at Midway, even assuming they had the industrial might of the United States, which they did not, it was still 16 to 24 months before they could replace the lost ships. 

Generals throughout history have risked their armies in decisive battles, but have been more reluctant when it comes to their navies.  The British horrifically threw hundreds of thousands into machine guns and entrenchments in the Battle of the Somme, but were far more reluctant to do so. Yet there are a few admirals with long resumes and several battles in history that should slake even the greatest hunger of those who love military history.  

Few military leaders in world history have achieved the reputation for brilliance, integrity, and resilience that surrounds Admiral Yi Sun-sin of the Joseon Dynasty. Born in 1545 and active during the late sixteenth century, Yi rose from relative obscurity to become the savior of Korea during the catastrophic Japanese invasions of 1592–1598, known as the Imjin War. Through extraordinary tactical genius, unyielding discipline, technological innovation, and personal moral courage, he repeatedly defeated larger enemy fleets, protected the Korean homeland from collapse, and left behind a legacy that endures in both Korean historical memory and global military scholarship.

We will explore his rise, his revolutionary naval reforms, his triumphs during the Imjin War—including the famed turtle ship—his political struggles and momentous return to command, and his lasting legacy as one of the greatest admirals of all time – but the greatest? That will come later on in this podcast.  And though I will try to avoid the obvious hagiography that would necessarily descend around one of Korea’s (North and South) great heroes, in composing this podcast and studying the man, I must confess to a bit of hero worship myself.  

Yi Sun-sin was born on April 28, 1545, in Asan, into a once-prominent but economically modest yangban (aristocratic) family. From a young age, Yi demonstrated talent in archery, horsemanship, and classical Confucian learning. His upbringing combined martial discipline with Confucian moral ideals—particularly loyalty, integrity, and devotion to the state—traits that would later define his service.

Yi failed his first military exam due to an accident during the test, but returned after several years of self-training, eventually passing with distinction. His early postings involved frontier defense against Jurchen tribes in Korea’s north, where he developed a reputation for strict discipline and fairness. Unlike many officials of the time, Yi was incorruptible; he refused to take bribes, avoided nepotism, and insisted on maintaining military readiness even during peacetime.

These traits, while admirable, made him enemies in a deeply factionalized Joseon political system. This political vulnerability would repeatedly haunt him, even as he rose to greatness.

By the late 1580s, Yi Sun-sin was appointed commander of the Left Naval District of Jeolla Province. Alarmed by growing Japanese piracy and militarization under Toyotomi Hideyoshi, Yi rapidly transformed Joseon’s naval preparedness.

His reforms included:

Yi implemented rigorous daily drills for gunnery, ship maneuvering, formation practice, and archery. He reestablished supply lines, improved logistics, and carefully monitored every aspect of his command.

He ordered the repair of dozens of neglected warships and reorganized shipbuilding to ensure consistency and durability. His fleet relied heavily on Geobukson (guh-book-sun), also called turtle ships, sturdy, multi-decked wooden ships well suited for Korea’s coastal waters.

Yi is credited with the resurrection and refinement of the turtle ship, a covered, armored vessel with iron spikes on its deck, a dragon-head prow capable of releasing smoke to obscure visibility, and multiple cannon ports on all sides. Though not as numerous as legend suggests, these ships had enormous psychological and tactical value.  My mind stretches to other military innovations that could change the tide of battle, like the Macedonian Phalanx or the Indian war elephant.  Not the core of the army, such as a Roman Legion, but a weapon that could be deployed and turn an even contest into a lopsided one.  

Admiral Yi described his proposed turtle boat as follows:

“The bow is equipped with a dragon’s head through which cannons are fired.  The upper deck is covered by an armor plate to which sharp knives, spear heads, and spikes are attached.  The crew can sight the enemy and fire cannon through gun ports while remaining under the protection of the armored deck”. Some further description is offered in a book published in 1795, almost two hundred years after the admiral’s death. It notes that: “In the bow was the turtle’s head, four feet three inches long by three feet wide. There was a combination of sulfur and saltpeter that was burned, which emitted great clouds of smoke”.

In 1592, Toyotomi Hideyoshi launched one of the largest amphibious invasions in premodern East Asia. Frequent listeners have already met Hideyoshi in my Long Way to the Top podcast, as Hideyoshi rose from a peasant to rule Japan.  But his ambitions did not stop there.  

Japanese forces overwhelmed fortresses, captured Seoul and Pyongyang, and inflicted severe devastation. Amid this chaos, Admiral Yi Sun-sin—largely left to prepare on his own initiative—became Korea’s primary defensive bulwark. Hideyoshi’s ambitions were massive, thinking of Korea as the stepping stone to the real prize, the Chinese Ming Empire. “I hope that Korea will be my vanguard. Let her not fail to do so, for my friendship for your honorable nation depends on your conduct when I lead my armies against China.” It was not the last time Japan would attempt to achieve East Asian dominance, but I digress.  

As noted, Yi achieved a series of massive victories against Japanese forces over the seven years of the Imjin War.  

The 1592 battles

Battle of Okpo

Yi’s first engagement was a decisive victory, destroying dozens of Japanese transport ships. Although small in scale compared to later battles, it provided morale at a moment of national despair.

Battle of Sacheon (Sah-chun)

Here, Yi debuted the turtle ship to devastating effect. Using feigned retreat tactics, he lured the Japanese fleet into an exposed position and annihilated it. The combination of cannon fire and shock value set the tone for the war.

Battle of Hansan Island 

Often considered Yi’s masterpiece, this battle employed his famous “crane-wing” formation, which enveloped and destroyed a superior Japanese force. The victory secured control of the southern sea lanes, severing Japanese supply lines and preventing reinforcements from reaching the northern Korean interior.  Many historians regard the Battle of Hansan as one of the greatest naval battles in East Asian history.

By this unbroken series of victories, Yi-Sun Sin had, in the short space of six weeks, destroyed the Japanese sea power and ap­plied a death grip on the Japanese armies in Korea by cutting them off from all supplies and reinforcements. The invaders were thrown on the defensive and forced to re­treat to the coast under greatly adverse conditions to save themselves from the fate of their fleets.

The Pinnacle of Strategy and Morale

Between mid-1592 and late 1597, Yi maintained total command of Korea’s coastal waters. He protected civilian refugees, shielded supply routes from Japanese raiders, and prevented Japan from establishing stable logistics on the peninsula. Even when outnumbered, he carefully chose battlefields where geography favored his heavier, cannon-armed ships.

Japanese commanders grew to fear him. Their own reports lamented:

“It is difficult to fight the Joseon navy because they have an admiral like Yi Sun-sin.”

Can a military leader be too successful?  Throughout history, there have been plenty of examples.  The Roman Scipio Africanus had to be brought low.  Justinian of the Eastern Roman Empire came to see his great general Belisarius as a rival, and even Douglas MacArthur, who brought much of the ignominy on himself, was dismissed after another Korean conflict.  It was the same with Yi.  Despite his successes, political rivals in the Joseon capital—motivated by jealousy, factional infighting, and misinformation from Japanese defectors—convinced King Seonjo that Yi disobeyed orders. He was arrested, tortured, stripped of rank, and nearly executed.

Only the military’s insistence on Yi’s innocence spared his life. He returned to service as a common soldier. Even in humiliation, Yi distinguished himself through discipline and loyalty.

Return to Command and the Miracle at Myeongnyang (Myeong-yang)

Joseon’s (Jo-See On) replacement admiral, Won Gyun, immediately suffered a catastrophic defeat at Chilcheollyang (Che Chelol Yang), losing nearly the entire fleet. Japan regained naval momentum and threatened to cut off Ming Chinese reinforcements.  In desperation, Yi was reinstated. Finding only twelve surviving ships, he faced hundreds of Japanese vessels. Yi is supposed to have said, when the Korean king demurred on any further naval battles, “Your Highness, I still have twelve battleships.”

Battle of Myeongnyang (1597)

Through ingenious use of treacherous local currents, narrow straits, and staggered formations, Yi turned twelve ships into an unbreakable blockade. The Japanese fleet was funneled, confused, and crushed. Yi won a stunning victory, preventing the Japanese from advancing north and giving Korea a chance to recover.  Military historians often rank this triumph alongside Trafalgar and Salamis.

Final Campaign and Death at Noryang (1598)

In 1598, as the Japanese prepared to withdraw, Yi coordinated with Ming Chinese naval forces to destroy a significant Japanese fleet at the Battle of Noryang. It was a decisive victory—but it cost Yi his life.

Struck by a stray bullet, Yi whispered:

“Do not let the battle stop. The war is not over—do not announce my death.”

He died as he lived: committed entirely to his duty.

And into this narrative we will now insert the figure, the only admiral in the history of the world, whom I would rank above Yi, and that is Admiral Horatio Nelson.  Why at this point in the podcast?  Both died in their penultimate battles, the one that ensured the survival and prosperity of their nations for the next 100 years.  

Now, if you want an incredible treat.  View the Yi Trilogy. It is a little confusing.  The first movie, The Admiral: Roaring Currents (Myeongryang) in Korean, released in 2014, takes place after the events of the second movie, released in 2022. The second was called Hansan: Rising Dragon.   The third concludes with Noryang and Yi’s death (sorry, that is a spoiler).  In all three movies, Yi is portrayed by different actors, and each has both English and Korean titles.  You can watch them with subtitles or dubbing. I tend to prefer the former, as dubbing can be a bit distracting.  

But the depictions and special effects are incredible.  You feel as if you are seeing the actual battles with hundreds of ships on both sides.  Of course, since these movies are made as Korean national emblems, Yi is always noble and decisive.  The Japanese are slightly unhinged, and everyone is very dramatic.  But the reality was that by the time of these events, the Japanese would have been somewhat unhinged because they were no longer just fighting Yi, his fleets, and the incredible Turtle Ships; they were also fighting Yi’s reputation.  It is like you are a good basketball player, but you are playing against Prime Michael Jordan or LeBron James.  It could not help but get into one’s brain.  

Yi Sun-sin’s legacy rests on several pillars: Yi never lost a single battle at sea. His understanding of tides, geography, formations, and firepower was exceptional. He embodied Confucian virtues yet combined them with practical military leadership. His war diaries, the Nanjung Ilgi, reveal his humility, discipline, and constant concern for the welfare of his men. His refinement of the turtle ship and modernization of naval logistics helped level the playing field against a larger, more experienced invading force.  

The case for Yi over Nelson is his achievements without losing a single engagement, and often with drastically inferior numbers.

As noted earlier, in Korea today, Yi represents patriotic resilience, strategic brilliance, and moral righteousness. Statues honor him in Seoul and across the nation, and the Korean Navy reveres him as the founder of its maritime tradition.

Was Yi the Greatest Admiral of all time?  I think he has only one rival, British Admiral Horatio Nelson.   Admiral Ballard, the English naval his­torian, wrote,

It is always difficult for an Englishman to admit that Nelson ever had an equal in his profession, but if any man is to be so regarded it is undoubtedly this great naval commander of Asiatic race who never knew defeat ... of whose movements a track chart might be compiled from the wrecks of hun­dreds of Japanese ships lying with their crews at the bottom of the sea.

Why Nelson?  Yi fought all his battles against one foe in his home waters.  Nelson fought in a bay outside Alexandria against the French, in a bay outside Copenhagen against the Danes, and at Trafalgar against the Spanish and French.  Different foes, different waters, and different tactics.  Also, his conduct as a subordinate at Cape St Vincent under Jervis, or near insubordination at Copenhagen under Parker, puts him in a different context than Yi, who was in Supreme Command.  Nelson had to overcome not only his enemies but the mistakes of his superiors.  

And I have mentioned the special effects of the Yi Trilogy.  Really wish some wealthy Brits created a Nelson trilogy.  You could do Young Nelson, then Nelson at Cadiz and Aboukir Bay, and conclude with Copenhagen and Trafalgar, because in one of those incredible parallels that make history greater than any fiction, Nelson too died at the penultimate battle that ensured the peace of his nation from a foreign invader.  

Regardless, this type of ranking sometimes clouds the fact that these were very great military leaders.  

Admiral Yi Sun-sin’s life stands as a testament to the impact a single, moral, and exceptional leader can have on the fate of a nation. In the face of overwhelming invasion, political betrayal, and devastating loss, Yi’s steadfast loyalty, personal courage, and naval mastery preserved Joseon from total collapse.  He remains not only a Korean hero, but a towering figure in world military history—a commander whose victories reshaped the course of a war and whose principles continue to inspire centuries later.