Chung Mu is the given name of great admiral Yi Sun-Sin who was in charge of naval operations during the Joseon Dynasty. Born in 1545, Yi Sun-Sin was considered a master naval tactician and was largely responsible for the defeat of the Japanese in 1592 and 1598. He has been compared to Sir Francis Drake and Lord Nelson of England. His name is held in such high esteem that when the Japanese fleet defeated the Russian navy in 1905, the Japanese admiral was quoted as saying, "You may wish to compare me with Lord Nelson but do not compare me with Korea's Admiral Yi Sun-Sin.... He is too remarkable for anyone."

Yi Sun-Sin's most famous invention was the Kobukson, or turtle-boat, a galley ship decked over with iron plates to protect the soldiers and rowing seamen. It was so named because the curvature of the iron plates covering the top decks resembled a turtle's shell. The ship was 110 feet long and 28 feet wide with a lower deck for cabins and supplies, a middle deck for oarsmen, and an upper deck for marines and cannons. Most of the timber was four inches thick, giving the ship protection from arrows and musket balls. It had a large iron ram in the shape of a turtle's head with an open mouth from which smoke, arrows, and missiles were discharged. Another such opening in the rear and six more on either side were for the same purpose. The armored shell was fitted with iron spikes and knives that were covered over with straw or grass to impale unwanted boarders.

The Kobukson was not only impervious to almost any Japanese weapon, it was heavy and built for speed and could overtake anything afloat. The ship carried approximately forty 3-inch cannons that fired shot or steel headed darts, and had hundreds of small holes for firing arrows or throwing bombs. In comparison, the Japanese ships usually carried one cannon, many muskets, and no protective armor. The Kobukson was very effective in chasing down and sinking large numbers of Japanese troop and supply ships as well as successfully attacking numerous heavy Japanese battleships head on. It was the most highly developed warship of its time.

The Kobukson was constructed in a critical period in Korean history, one of the many times Korean and Japanese destinies converged.

First invasion in 1592
When Toyotomi Hideyoshi, the shogun of Japan, rose to power in 1590, he decided to control the internal feuding in Japan. Because Japan's largest threat was the other powerful war lords of Japan, he planned to tie up the financial resources of the lords with an invasion of China and thereby dilute their power. He requested that Korea aid him in his conquest. When it refused, he ordered two of his generals, Kato Kiyomasa (the Buddhist commander) and Konishi Yukinaga (the Christian commander), to attack Korea in April 1592.

The Japanese invasion force was comprised of 160,000 regular army troops, 80,000 bodyguard troops, 1,500 heavy cavalry, 60,000 reserve troops, 50,000 horses, 300,000 firearms 500,000 daggers, 100,000 short swords, 100,000 spears, 100,000 long swords, 5,000 axes, and 3-4,000 boats (40-50 feet by 10 feet). The army was also supported by another 700 ships, transport vessels, naval ships, and small craft manned by 9,000 seamen. Having been acquainted with the use of firearms since 1543, the Japanese had imported a large number of muskets from Europe, and had developed the ability to manufacture them four years before the first invasion.

The Koreans, on the other hand, had few firearms and did not know how to use or manufacture them. Outnumbered and armed only with swords, bows and arrows, and spears, the Korean military was severely disadvantaged in the face of the Japanese invading army armed with 300,000 muskets. Although a few courageous Korean units resisted, such as those under the command of General Kim Si-Min, the army of Japan reached Seoul in just 15 days and occupied the entire country by May 1592.

The Korean king, Son Jo, fled with his court to Uiju in the Northern Provinces with permission from the Ming emperor of China with whom the Koreans had several treaties. When the Ming armies joined in the fight, the tide of the war shifted away from the Japanese. They had to fight Korean guerilla groups as well as the Ming army, while at the same time finding themselves cut off from their supplies by Admiral named Yi Sun-Sin. Disease, malnutrition, and the cold soon took its toll on Japanese morale. Having lost the will to fight, retreating Japanese forces were stalked by guerilla forces led by Confucian scholars and Buddhist monks. Peace negotiations eventually took place between the Ming general and the Japanese, but these talks dragged on for five years and reached no conclusion.

In early 1592, at the outset of this conflict, Admiral Yi Sun-Sin, in charge of the Right Division of Chulla Province, made his headquarters in the port city of Yosu. In Yosu, he constructed his famed turtle ships. The first Kobukson was launched and outfitted with cannons only two days before the first Japanese troops landed at Pusan. In the fifth month of 1592, assisted by Admiral Won Kyun of the Left Division of Chulla Province, Admiral Yi engaged the Japanese at Okpa. In his first battle, Admiral Yi commanded 80 ships compared to the Japanese naval force of 800 ships. The Japanese were trying to re-supply their northern bases from their port at Pusan. By the end of the day, Yi had set afire 26 Japanese ships and the rest had turned to flee. Giving chase, he sank many more, leaving the entire Japanese fleet scattered.  Several major engagements followed in which Admiral Yi annihilated every Japanese squadron he encountered. Courageous and a tactical genius, he seemed to be able to outguess the enemy. In one incident, Admiral Yi dreamt that a robed man called out "The Japanese are coming." Seeing this as a sign, he rose to assemble his ships, sailed out, and surprised a large enemy fleet. He burned twelve enemy ships and scattered the rest. In the course of the battle, he demonstrated his bravery by not showing pain when shot in the shoulder. He revealed his injury only when the battle was over, at which time he bared his shoulder and ordered that the bullet be cut out.

In August of 1592, 100,000 Japanese troop reinforcements headed around Pyongyang peninsula and up the west coast. Admiral Yi and his Lieutenant Yi Ok-Keui confronted them at Kyon-Na-Rang among the islands off the southern coast of Korea. Pretending at first to flee, Admiral Yi then turned and began to ram the Japanese ships. His fleet followed his lead and sank 71 Japanese boats. When a Japanese reinforcement fleet arrived, Admiral Yi's fleet sank 48 more Japanese ships and forced many more to be beached as the Japanese sailors tried to escape on land. This engagement is considered to be one of history's greatest naval battles.

Unaware of this battle, the Japanese commander had sent a message to the Korean King Son-Jo that read: "100,000 men are coming to reinforce me. Where will you flee then?" Upon hearing that Admiral Yi had shattered the Japanese fleet, the king was elated and heaped all possible honors upon him. For the Japanese, any hope of an invasion of China was now totally crushed.  Admiral Yi Sun-Sin pushed on to Tang-Hang Harbor where he encountered another large Japanese fleet that included the huge Japanese flagship of the Japanese admiral. Admiral Yi ordered his best archer to shoot the Japanese admiral, who sat on the deck dressed in silk and gold. The arrow pierced the Japanese admiral's throat, throwing the entire Japanese fleet into a panicked retreat which ended in carnage as Yi pursued in his usual fashion.

In a brilliant military move, Admiral Yi took the entire Korean Navy, 180 small and large ships into the Japanese home port at Pusan harbor and attacked the main Japanese naval force of more than 500 ships, that was still at anchor. Using fire boats and strategic maneuvering, he sank over half of the Japanese vessels. However, receiving no land support, Admiral Yi was forced to withdraw. With this battle, Admiral Yi completed what some naval historians have called the most important series of engagements in the history of the world.

During one patrol sweep, Admiral Yi's fleet spotted 26 Japanese ships on the horizon. He spread out his forces in a formation known as the fishnet and advanced. The fishnet or inverted V grouped the heaviest ships of the fleet at its vortex. As the enemy ships were forced inside the V, they were trapped and destroyed by Yi's heavy ships.

Korean control of the sea, under the command of Admiral Yi Sun-Sin, soon forced the Japanese invasion to a complete standstill. Although the Japanese ground commanders begged for supplies, neither supplies nor reinforcements could get past Admiral Yi Sun-Sin to reach the Japanese forces along the western coast of the peninsula. Because of this situation, the following months saw little military action.

During his forced idleness Admiral Yi Sun-Sin prepared for the future; he had his men make salt by evaporating seawater, and used it to pay local workers for building ships and barracks and to trade for materials his navy needed. His energy and patriotism were so contagious that many worked for nothing. Having heard not only of Yi's military feats, but his contributions to the navy as well, the king conferred upon him the admiralty of the surrounding three provinces.

For a successful invasion of Korea, the Japanese knew that they would have to eliminate Yi Sun-Sin. No Japanese fleet would be safe as long as his turtle boats were prowling the sea. Seeing how the internal court rivalries of the Koreans worked, the Japanese devised a plan. A Japanese soldier named Yosira was sent to the camp of the Korean general, Kim Eung-Su, and convinced the general that he would spy on the Japanese for the Koreans.

Yosira spent a long time acting as a spy and giving the Koreans what appeared to be valuable information. One day he told General Kim that the Japanese General Kato would becoming on a certain date with the great Japanese fleet, and insisted that Admiral Yi be sent to lie in wait and sink it. General Kim agreed and requested King Son-Jo for permission to send Admiral Yi. The general was given permission, but when he gave Admiral Yi his orders, the admiral declined. Yi knew that the location given by the spy was studded with sunken rocks and was very dangerous. When General Kim informed the king of Admiral Yi Sun Sin's refusal to go, Admiral Yi's enemies at court insisted on his replacement by Won Kyun and his arrest. As a result, in 1597 Admiral Yi Sun-Sin was relieved of command, placed under arrest, taken to Seoul in chains, beaten, and tortured. The king wanted to have Admiral Yi killed but the admiral's supporters at court convinced the king to spare him due to his past service record. Spared the death penalty, Admiral Yi was demoted to the rank of common foot soldier. Yi Sun-Sin responded to this humiliation as a most obedient subject, going quietly about his work as if his rank and orders were totally appropriate.  With Admiral Yi stripped of any influence, when negotiations broke down in 1596, Hideyoshi again ordered his army to attack Korea. The invasion came in the first month of 1597 with a Japanese force of 140,000 men transported to Korea in thousands of ships. Had Admiral Yi been in command of the Korean Navy at that time, the Japanese would most likely never have landed on any shore again. Instead, the Japanese fleet landed safely at Sosang Harbor.

The spy Yosira continued to urge General Kim to send the Korean Navy to intercept a fleet of Japanese ships. When ordered to do so, Won Kyun gathered his 80 ships together and reluctantly set sail. This fleet was hardly recognizable as Yi Sun-Sin's former one. Won Kyun had eliminated all of the rules and regulations set up by Yi when he took command as well as purging the ranks of all who had been close to Admiral Yi. His inept maneuvers almost destroyed the entire Korean fleet and alienated all his men. Consequently, this battle ended in a complete defeat for the Korean Navy, while Yi Sun-Sin was being detained as a foot soldier. The Korean fleet scattered in a night storm and the main portion blundered upon the Japanese fleet the next day. On seeing the Japanese fleet, Won Kyun panicked and retreated. He beached his boats and took to the land but the Japanese overtook and beheaded him. The Korean fleet scattered was mostly destroyed.

With the news of Won Kyun's disastrous defeat, a loyal advisor of the king called for Yi Sun-Sin's reinstatement. Fearing for his country's security, the king hastily reinstated Yi Sun-Sin as the naval commander. In spite of his previous unfair treatment, Yi immediately set out on foot for his former base at Hansan. As he traveled, he met scattered remnants of his former force. By the time he arrived at Hansan, he had only twelve boats but no lack of men, for the people along the coast had flocked to him when they heard of his reinstatement. Yi drew up his fleet of 12 boats in the shadow of a mountain on Chin-Do island off the Myongyang straits. One night his scouts reported the approach of a Japanese fleet. As the moon dropped behind the mountain, the Korean fleet of 12 ships was shrouded in total darkness. When the Japanese fleet of 133 ships sailed by in single file, Admiral Yi's forces gave a large shout and fired point blank. Yi employed one of his tactics, the use of two salvo fire, that resulted in a continuous barrage, causing the Japanese to think that they had run into a vastly superior force. Their fleet scattered in all directions in a total panic. The next day several hundred more Japanese ships appeared and Admiral Yi, fearless as ever, made straight for them. He was soon surrounded, but sank 30 Japanese boats. The remainder of the Japanese fleet, recognizing the work of the famous Admiral Yi Sun-Sin, turned and fled. Admiral Yi gave chase, decimated the enemy, and killed the Japanese commander Madasi.

After this battle, Admiral Yi returned to Hansan and once again began rebuilding the navy and making salt. His former captains and soldiers came back to him in "clouds." With his salt-making operations and the money collected as a toll from fleeing merchant ships, Admiral Yi purchased needed plies and materials such as copper used in making cannons and ships. He again managed to establish a large, well-equipped garrison.   Despite Admiral Yi's personal success, Korea was alone and in trouble. What help was available was most often supplied by Chinese troops and naval units. Although this military support was welcome, it carried with it a new set of problems, such as Korean fighting units having to put up with Chinese commander being in charge of them. These commanders were usually not inspired by the same patriotism that guided good Korean commanders.

In 1598, the Chinese emperor sent Admiral Chil Lin to command Korea's western coast. Admiral Chil Lin was an extremely vain man and would take advice from no one. Knowing this to be a serious problem, Admiral Yi made every effort to win the trust of the Chinese admiral. His political skills proved to be as good as his military ones. He allowed Admiral Chil Lin to take credit for many of his own victories. He was willing to forgo the praise and let others reap the commendation in order to have the enemies of his country destroyed.

Yi Sun-Sin was soon in charge of all strategy while Admiral Chil Lin took the credit. This arrangement made the Chinese seem successful, which so encouraged them that they gave Korea the aid it desperately needed. Admiral Chil Lin could not praise Admiral Yi enough, and repeatedly wrote to the Korean King So-Jon that the universe did not contain another man who could perform the feats that Yi Sun-Sin apparently found easy.

The Admiralís statue towers over Seoul's Sejong Avenue
It is fitting that Admiral Yi died in battle in 1598. It was during the time when the Japanese were trying to evacuate many of their forces. Admiral Yi and the Chinese Admiral Chil Lin swooped down on their forces and nearly wiped out the entire fleet. On November 8, 1598, at the age of 54, Yi Sun-Sin, while standing in the bow of his flagship directing the battle, was struck with a stray bullet. Before he died, he is quoted as saying, "Do not let the rest know I am dead, for it will spoil the fight."

During the second invasion of Korea in 1597, the Japanese were only able to occupy Kyongsang and part of Chulla Provinces. Their efforts were thwarted by the harassment of the Korean volunteer army and the strategies of Admiral Yi Sun-Sin that prevented them from landing or being supplied beyond the southern provinces. Partly due to this lack of progress, the war ended after Hideyoshi's death late in 1598 when the Japanese troops were recalled to Japan.

The six years of war, from 1592 to 1598, laid waste to the whole Korean peninsula. Hardly a building still stands in Korea that predates the Hideyoshi invasions except for a few stone structures. Rare and valuable collections of books were destroyed, including the official records of the reigns of the Joseon Dynasty. A series of famines, epidemics, peasant revolts, and a full-scale renewal of political squabbling in the Korean government followed on the heels of the war. As a result, culture and government were left in chaos and the social system of the country was disrupted.

For all its disastrous aftermath, the war did provide Korea with one of its most celebrated national heroes, Admiral Yi Sun-Sin. Known primarily as an inventor of the world's first iron-plated vessel and a master naval tactician, Yi also had other accomplishments. Some of his little-known inventions included the use of a smoke generator in which sulfur and saltpeter were burned, emitting great clouds of smoke. This first recorded use of a smoke screen struck terror in the hearts of superstitious enemy sailors, and more practically, it masked the movements of Admiral Yi's ships.

Another of his inventions was a type of flamethrower, that was a small cannon with an arrow-shaped shell that housed an incendiary charge. This flamethrower successfully set afire hundreds of enemy ships. Along with his inventions, specific tactical maneuvers demonstrate Yi's brilliance as a naval tactician, such as his use of the fishnet formation and using two salvo fire against ships.

Admiral Yi Sun-Sin was one of the greatest heroes in Korean history. He was posthumously awarded the honorary title of Choong-Moo, "Loyalty-Chivalry," in 1643. The Distinguished Military Service Medal of the Republic of Korea (the third highest) is named after this title. Numerous books praise his feats of glory and several statues and monuments commemorate his deeds. In April 1968, a 55-foot high statue of Yi (reportedly the tallest in the Orient) was dedicated in Seoul, Korea. His life-size statue on the peak of Mt. Nam-mang, indicates he was a very large man, as judged by the size of the sword on the statue.

The shrine of Chungnyol-Sa, meaning "faithful to king and country," established in 1606, is now both a museum and shrine dedicated to the admiral. The eight relics on display in this shrine were gifts to Admiral Yi Sun-Sin from the Chinese emperor and include a 7-foot commander's bugle, a 5-foot sword, a ceremonial sword (weighing 66 pounds), Admiral Yi's seal, and several flags. Another Korean treasure is the war diary of Admiral Yi Sun-Sin, which, in addition to some of his personal articles, is preserved at the shrine of Hyonchung-Sa. At the shrine are preserved Admiral Yi's war diaries as well as some of his personal belongings. Near the shrine stands a gnarled old gingko tree under which the admiral practiced archery during his youth. A replica of a Kobukson as well as other articles of that period are displayed in a small museum. In addition, a small museum in the city of Choong-Moo, a traditional seaport named after him, displays a replica of the turtle ship as well as other articles of that period.

Perhaps one of Yi Sun-Sin's greatest qualities was his drive to serve his king and Korea in any way he could. When almost everyone in Korean politics and military service was forced to side with one of the two powerful Korean political parties of the time to survive the ruthless atmosphere, Yi chose neither and was only loyal to his king and country. Moreover, at a time in Korean history when position and rank meant everything, Yi Sun-Sin demonstrated a remarkable ability to maintain his pride in the face of an unwarranted demotion. Any other officer of his time would have been driven to suicide or revenge in an attempt to erase such a terrible disgrace. Yi, however, merely went about his work as a common foot soldier without a thought for these courses of action. Not only a naval innovator and tactician hundreds of years ahead of his time, Yi was also a man with bravery and loyalty matched by few in the history of the world.  

The hyung ends with left hand attack to symbolize Admiral Yi's regrettable death and not having a chance to show his loyalty to the king.