Kobuksan, Panokseon, Geobukseon, Jija, Hwatcha, Hwando, Woldo, Composite Bow, Triple-Barrel Pole Gun
Yi Sun Shin was born in 1541 in Hanseong, in Joeson Dynasty Korea, an area that is now part of Seoul, South Korea. The Yi joined the military, proving to a skilled swordsman and archer in the military examination, though he did failed the cavalry exam due an accident resulting in a broken leg. While Yi is best known as an admiral, his first military campaigns on land, against a Manchurian people known as the Jurchen. Yi proved to be a skilled tactician, defeating the Jurchen in a series of battles and capturing their leader.
However, Yi's superiors drew jealous of his success and conspired to falsely accuse him of desertion. Yi was arrested and imprisoned, but eventually released and allowed to rejoin the military as an enlisted soldier, however, he again climbed through the ranks for his tactical brilliance, being placed in command of Yoesu in 1591, where he took charge of building up the region's naval forces.
In 1592, the Japanese, having been unified under samurai warlord Toyotomi Hideyoshi, invaded Korea with a massive fleet of 7000 ships, intending to use it as a staging ground for Hideyoshi's eventual plan, the invasion of Ming Dynasty China. While the Japanese quickly defeated the Korean army on land, Yi defeated the Japanese in a series of battles, even though he never studied naval warfare at a military academy. Yi played to his strengths and his enemies weaknesses, avoiding allowing the Japanese to board and engage in hand to hand combat where they excelled, and instead using his more heavily armed panokseon warships- armed with 20 or so cannon, to outgun the smaller Japanese ships with only one or two cannon.
Yi won every major battle in 1592 that he was involved in. At the first major battle, at Okpo, where he sank 11 Japanese warships while losing none himself. Then, at Saechon, Yi deployed his new secret weapon, an armored-hulled (sources vary on whether it had iron plates or only a wood roof, regardless, it was resistant to cannon fire), spike studded warship armed with about 20 cannon known as the kobuksan, or turtle ship. Admiral Yi and his turtle ships annihilated the Japanese fleet at Saechon In later battles, he would also suffer no losses, while sometimes destroying over 20 Japanese ships.
At the Battle of Hansan island, Admiral Yi used tactics similar to the late 19th and early 20th century battleship tactic of "Crossing the T"- turning broadsides to the enemies bow to maximize your firepower and minimize the enemies. With this tactic, Yi again wiped out the Japanese fleet of over 50 ships without losing a single vessel. later, Yi went on to attack the Japanese in Busan Harbor, destroying over 100 enemy ships.
Yi almost met his downfall after Busan, when a Japanese double agent gave Yi false coordinates for his fleet, however Yi knew the location had numerous sharp rocks, and refused to sail to the location. This refusal got Yi arrested gain and tortured almost to death. King Seongjo of Korea wanted to have Yi executed, but the Yi's supporters convinced the king to spare him, though he was once again demoted to foot soldier, and the incompetent admiral Won Gyun was placed in charge of the fleet.
Won Gyun was defeated decisively by the Japanese at Chilchonryang, which resulted in Won Gyun himself being killed in battle. Yi went on to prove himself in what was no doubt his greatest acheivement, at Myeongnyang, aided by unpredictable current and the shadows of land behind him hiding his ships position, Yi managed to defeat a fleet of over 300 Japanese ships, destroying 33, damaging 92 and forcing the rest into retreat.
At the Battle of Noryang, Yi and his fleet of 85 ships including three turtle ships, along with an allied Ming fleet of 65 ships, Yi forced a large Japanese fleet into retreat, however, he was killed in action by a stray musket ball from an enemy ship. Nonetheless, the Koreans won the battle, and the Japanese gave up their designs on the conquest of Korea.
Admiral Yi was known as a charismatic and inspirational leader, as well as a master tactician and skilled personal combatant, known to have fought alongside his men on the rare occasions where boarding actions did occur. Today, Yi Sun-Shin is remembered as one of the greatest heroes in Korean history, and as one of the greatest admirals in history, praised by numerous later admirals, earning praise from even his Japanese adversaries, and a being described as comparable, or even surpassing the tactical genius of Admiral Horatio Nelson.