The Admiralship of Yi Sun-sin

Following are some of the key features of Admiral Yi Sun-sin’s leadership, which lay behind every legendary naval victory that he won.

1. Thorough preparation and intensive training

Before the war and throughout it, and even during the truce, Admiral Yi always subjected his men to intensive training in archery, artillery, and the various standard naval maneuvers and formations. He also tirelessly engaged himself in manufacturing new weapons and building ships. For example, only a year after the Battle of Myongnyang which he fought with a mere thirteen ships, he had succeeded in building 70 more – an astonishing rate of one new ship every five days.

2. Careful study of the nature of the battlefield and its layout

The southern coast of Korea, the scene of many fierce sea battles between Korea and Japan during the Seven Year War, was a maritime labyrinth, consisting of countless isles and inlets. Furthermore, the current is very fast and the long stretching coast provided a completely different appearance with the rise and fall of every tide. Yi made a careful study of the hourly changes of currents and winds, as well as the natural features peculiar to each naval battlefield. Based on his investigations, he was able to rely on a safe sea-route whenever he moved his fleet by night escaping the eye of the enemy. As evident from the battles fought at Hansan and Myongnyang, his foreknowledge allowed him to turn the complex geographical features of the coast to his advantage when pursuing or being pursued by an enemy.

3. Diverse use of naval tactics

Admiral Yi used a wide variety of naval tactics in sea battles besides the famous Crane Wing Formation.[1] In his first battle at Okpo, he arranged his fleet in horizontal line and made straight for the enemy fleet at full speed, thus not allowing them the least room to maneuver or escape and pressing them close with fierce cannon fire. In the sea battle at Pusan, the Long Snake Formation (Kor. Chang Sa Jin) was used in order to deal with the formidable odds – 83 Korean ships against 480 Japanese. Yi adopted this long, narrow formation to minimize the exposure of his fleet to the enemy’s fire. Korea emerged victorious from this battle, sinking 128 enemy ships and losing none herself. In the Battle of Happo, Yi’s fleet droved the enemy fleet into a confined harbor, and was thus able to destroy all of its ships. In that engagement, Yi had no need to use formal naval formations, but simply ordered his ships to dash forward individually against the enemy as he judged fit. 

4. Undermining enemy morale and winning the trust of his men

  During naval engagements, Yi’s navy subjected the enemy to a bombardment of arrows and cannon shot from the outset, a tactic which proved highly effective in weakening the enemy’s fighting morale, and finally getting the better of them. As a consequence, Korean sailors developed an absolute trust in their admiral, and their morale grew higher and higher with every victory to which he led them.

5. Maintaining perfect discipline and strict principles

Lazy officers were rewarded with strokes of the cudgel, regardless of their rank. Soldiers who deserted the army were punished with death, as were officers who accepted bribes and overlooked their desertion, and indeed any man who was found to have committed the same crime more than once. At the Battle of Myongnyang, Yi angrily reproved An Wi, who had fallen back out of fear, threatening him with death under court martial if he did not heed his call to advance, and his words awakened An Wi to recover his spirit and fight. Admiral Yi’s emphasis on strict obedience to martial law and the maintenance of absolute discipline meant that the whole Korean Navy, from the supreme commander to the common soldier, were firmly united as one and were thus able to carry out naval formations and tactics which demanded strong unity among crew members successfully.

6. Fellowship and Duty

Although Chinese Admiral Chen Lien had attempted to hinder Yi’s plan to destroy the retreating Japanese force, the admiral rescued Chen when he was encircled by enemy ships at Noryang, and in danger of being captured. In the Battle of Myongnyang, An Wi abandoned his loyalty to his commander at the sight of the enemy’s overwhelming numbers, but was later saved by the admiral when he fell into trouble. Yi was always faithful to his principles and would not permit injustice or irresponsibility in his men. But at the same time, he harbored a deep sense of fellowship and obligation to them and so gained their trust, respect and devoted service.

7. Leadership overcame the worst conditions

Throughout the Seven Year War, Admiral Yi alone undertook to provide for every aspect of warfare, from supplies and provisions to recruitment and shipbuilding, having no support from the government. In battles where overwhelming odds were involved, he led his navy from the front to inspire his men with his valor and zeal. In the desperate situation before the Battle of Myongnyang, when the Korean Navy had only thirteen ships with which to fight, Yi was able to re-arm his men, with the dauntless soldier’s maxim “He who seeks death will live, and he who seeks life will die.”

Behind all these methods and devices lie Yi’s unshakable loyalty and selfless dedication to his country and people. In the course of abiding by them, Yi had to endure endless trials and sufferings. He remained loyal to his country, however, even after imprisonment, torture, and ignominious demotion to the ranks, since he firmly believed that remaining at sea and defeating the enemy was the one thing he could do for his nation. It is this splendid patriotic devotion that could be seen as the most powerful and important strategy of Admiral Yi Sun-sin.

Naval Battles of Admiral Yi Sun-sin

During the Seven Year War, Yi Sun-sin had engaged in twenty-three naval battles against Japan and emerged victorious in all of them. The naval battles fought by the Admiral can be summarized in a chart as follows.

Won Kyun was instated as the Supreme Naval Commander in Yi’s place while he served as a common foot soldier, and led three sea battles which ended in the Korean Navy’s worst catastrophe.

All dates are based on lunar calendar, which was used in East Asia until the late nineteenth century.

In addition to the 23 sea battles, several minor engagements took place. These include an assault by the Korean Navy on the Japanese naval base, and its successful defense of its own camp from the Japanese.

* The number of ships involved and the outcome of each naval engagement as shown in the charts have been taken from Admiral Yi’s War Diary and Memorials to Court, as well as from the Royal Archives of the Choson Dynasty, the official record of the government.

* Throughout the Seven Year War, the Korean Navy under Admiral Yi suffered some casualties but lost no ships; only two ships were lost by the mistake of captains on their way back to the base after the engagement at Woongchon. Such overwhelming victories by the Korean Navy may be attributed to the structural integrity of their ships, built in durable design and material, and the superior firepower and range of their naval artillery. The Japanese armed their vessels with only one to three cannons with much less firepower, and their main weaponry, muskets were effective in killing enemy sailors but not in destroying enemy ships. Yi thus utilized the strategy of sinking the enemy warship with concentrated cannon-fire before the distance between their ships had narrowed down to the musket range of 200m. In short, the Korean Navy could achieve successes unparalleled in the history of naval warfare due to Yi’s forceful strategy based on the superiority of Korean ships and guns.

* Of the twenty-three battles Yi had fought, the largest and the fiercest was the Battle of Noryang, the final engagement that put the 146 ships of Korea and China against the 500 of Japan carrying back their entire army on retreat home. The long, seven-year war, originating from the delusive ambition of a man in search for fame and territory, had taken away countless innocent lives and utterly destroyed their homeland. Boarding every supply and weapon he had onto warships, Yi headed for Noryang to carry out his final duty for his country and people. He took off his armor and helmet and fought at the heart of the battle, firing arrows and beating the war drums himself. He had never before taken off his armor or helmet in action. Perhaps it had been his resolve to end his difficult, arduous life with this last victory at sea. When he died by an enemy bullet, neither his crews nor the Chinese Navy knew of his death. They poured their hearts and souls into defeating the enemy till the very end and achieved the resounding victory that saw the sinking of 450 Japanese warships out of 500. It was the most honorable and precious victory for the Korean Navy earned in sacrifice of the admiral’s life.

With his last breath, he said, “Tell no one of my death.” He was concerned that his death might encumber the fighting against the enemy.

The Warships and Weaponry of Korea and Japan

During the Seven Year War, the Korean navy used both Panokson and Kobukson warships. The Panokson was the mainstay of the navy, while one to three Kobukson at would be used as the main assault ships. The ships of the Japanese navy consisted of the large Atake, the medium-sized Sekibune and the smaller Kobaya. The Atake served as the flagship, carrying on board the commanding admirals, while the medium-sized Sekibune comprised the greater part of the rest of the navy.

A key feature of the Korean Panokson was its multiple decks. The non-combatant personnel were positioned between the main-deck and the upper-deck, away from enemy fire. The combatant personnel were stationed on the upper-deck, which allowed them to attack the enemy from a higher vantage point. The Japanese fleet serviced mostly single-decked vessels, with the exception of a few large Atake.

In line with the traditional structure of Korean ships, the Panokson had a flat base. This feature was due to the nature of the Korean seacoast, which had a broad tidal range and flat, expansive tidelands. A level underside enabled a ship to sit comfortably on the tideland when the tide was out, after coming ashore or inside a wharf at high water. It also ensured greater mobility and a light draft and in particular allowed a ship to make sharp changes of direction at short notice. This Panokson was one of the main reasons why Admiral Yi was able to employ the Crane Wing formation at the Battle of Hansan with such success.

By contrast, the hulls of the Japanese vessels were V-shaped. A sharp underside was favorable for swift or long-distance travel because of lower water resistance. Since this variety of hull had a deep draft, however, the ship’s turning radius was considerable and changing direction was therefore a lengthy process.

Both Korean and Japanese ships used sails and oars. Of the two basic types of sail, square and lateen, the square gives a strong performance downwind but struggles windward, whereas the fore-and-aft lateen sail excels against the wind, though requiring a large crew to handle it. In the West, square sails were used in the galleys of Ancient Greece and the Viking longships, and the fore-and-aft variety later in the Mediterranean ships of the Late Middle Ages. When the Age of Exploration began in the fifteenth century, multiple-masted ships equipped with both types of sails eventually appeared. In Korea such ships had been in use since the eighth century. Korea’s Panokson and Kobukson therefore had two masts by default, and their position and angle could easily be managed so that the sails could be used in all winds, whether adverse or favorable[2]. The Atake of the Japanese Navy also had two masts, but the main parts of its vessels were square-rigged and their sails limited to use in favorable winds.

It is worthwhile also to compare the hulls of the two nations’ respective warships, and their relative strength. The Panokson used thick, high density boards, giving an overall sturdiness to the ship’s structure. Japanese warships were weaker, due to the thin, lower density timber used to build them[3]. The Sekibune in particular, being the standard warship of the Japanese fleet, was built to be as light as possible, increasing its speed at the expense of structural integrity.

The Panokson was not only built using thicker timbers, but its general structure was held together by means of wooden nails, matching indentations, and interlocking teeth. This meant that as its boards absorbed water and expanded, the greater integrity of the hull was made stronger. The Japanese warships, on the other hand, relied on metal nails which, as time passed and corrosion and rust set in, eventually weakened the hull.

This difference in structural integrity, which also determined the number of cannons that could be carried on board, suited Japan and Korea to different types of naval combat. Because the Japanese ships lacked the strength to withstand the recoil of cannon, even the largest ship Atake could carry only three at the most. Since the hulls of Korean warships were strong enough, however, they were able to carry a large number of long-range cannons. These could be installed with ease on the large upper-deck of the Panokson ships, and their angle configured at will to increase the range.

Since the Japanese warships only allowed for a very limited number of cannons, their sailors mainly used muskets, which had a range of 100-200m (330-660 ft). Korea, on the other hand, had on board several varieties of cannon, such as Heaven, Earth, Black and Yellow. They fired daejon (a long, thick arrow in the shape of a rocket) with a range of 500m (1,650 ft), as well as chulwhan (cannon shot) which could travel up to a distance of 1km (3300 ft). Wangu, a kind of mortar, which fired stones or shells with a radius of 20cm (7.8 in), was also used by the Korean navy.

Another noteworthy aspect of Korea’s heavy fire-arms is that they were not all invented to meet the sudden emergency of war. These weapons in fact made their appearance some 200 years prior to the Seven Year War. Thanks to the efforts of Choi Mu-son, a general and a chemist, Korea began manufacturing and developing gunpowder and power-based weapons. Korean cannons first saw action in 1380 against a large fleet of Japanese pirate ships, and were found to be a great success. In comparison, the first naval battle to have employed cannons in Europe was the Battle of Lepanto (1571), 200 years later.

In the 15^th century, under the lead of King Sejong, who was himself a pioneer of scientific research, the performance of these heavy artillery improved dramatically. Having built a cannon range next to the Royal Court, and after much experimentation and study, King Sejong finally increased the extent of the cannons’ firepower from 300m (980 ft) to 1800m (60,000 ft). Naval canons were also developed at this time and among them, Heaven, Earth, Black and Yellow cannon were later employed by Yi Sun-sin. The development of artillery steadily continued after King Sejong, and saw the invention of the Bikeokjinchonlae, a time-bomb that flung out hundreds of metal shards upon explosion, and the Dapoki, a machine capable of firing many arrows at once.

   The main naval strategy employed by the Japanese was that of "grapple-and-board", whereby sailors would attempt to board an enemy ship and fall to sword fighting on the decks. The Japanese Navy's concept of sea battle was therefore one of a fight between crews rather than the vessels themselves. This was the most common naval strategy in the world during this time, and was as common among the Europeans of the day. The Korean Navy, however, utilizing superior warships and firepower to burn and sink the enemy vessels, thus engaged in a more modern type of naval warfare.

Comparison between Korean and