Yi's family became distinguished with the beginning of the Joseon Dynasty. Yi Don-su's 5th generation son Byeon served during the Joseon Dynasty as a Yeongjung Directorate of Advisers official and Academician of the Office of Special Advisors and Yi's great-grandfather
Geo went up as high as the Councilor of the Ministry of Military Affairs. Yi's grandfather Baeknok, taking sides with the Younger Faction who were advocating political reforms and was involved in the disaster of the Literati Purge of the year Gimyo (1519). Thereafter, Yi's father was not interested in a government post and his family's financial condition had already hit rock bottom when Yi was born. Nevertheless, it was due to the influence of his mother Byeon that Yi was later able to accomplish brilliant achievements for his country as a great commander. Yi had two elder brothers, Hui-shin and Yo-shin, and one younger brother U-
shin, making up four brothers in all. Yi was courageous, charitable, loyal, had good poetic skills, and had a strong sense official piety, as was tradition for families of high-ranking government officials. Growing up with Yu Seong-ryong in the same village, he was always a leader in war games and was brave and smart enough to win every time.
Taking interest in the state military service examination, Yi took the examination for the Military Training Command at the age of 28. Unfortunately, however, the horse he was riding on fell at the examination site and Yi broke his left leg, disqualifying him. Undaunted by this failure, however, Yi continued to polish up on his military skills and finally passed the state military service examination four years later in 1576 in the ninth year of the reign of King Seonjo, and was appointed as the head of the Gwonji Military Training Command. Later, Yi was promoted to the position of Nokdo Garrison Farm Officer, where he met a turning point in his life. After taking office, Yi made an official tour of the area under his responsibility. Unsatisfied with his defenses, he wrote to the central government, asking them to send additional soldiers to strengthen the defense of the area under his responsibility. However, the King turned down Yi's request for additional soldiers. Some time later, Jurchen tribes invaded Yi's district and with his small number of soldiers put up a good fight. However, overwhelmingly outnumbered by Jurchen soldiers, Yi had to hide himself. The government, however, took issue with this and reprimanded him. Unafraid that he might be punished, Yi strongly defended himself and avoided a severe punishment but was stripped of his military rank and had to serve as a commoner. After this setback, Yi rose through several ranks and was appointed as the Associate Commander of Gosari, and then was further promoted to Magistrate of Jindo as a general. At the age of 47, Yi was appointed as Commander-in-chief of the naval forces of Jellado.
Taking charge of the naval forces as Commander-in-chief, Yi started to build the war ships around the base of Jwasuyeong (currently, Yeosu) and increased the military supplies in anticipation of an invasion by Japan.
In April 1592, the Japanese invaded. the Joseon Dynasty, which had enjoyed peace for so long and neglected to build its military power, was caught completely by surprise. On the first day of the Japanese Invasion, Fortress Dongnae in Busan was captured by the invading enemy troops, and the Choseon Army, despite continued augmentation by the government kept retreating.
Then King Seonjo suffered the disgrace of retreating to Uiju, but Yi Sun-shin, having gathered all the naval forces under his command, won naval battles at Okpo and Danghwangpo. Yi continued to defeat the Japanese navy...
After Yi won a great victory at Hansando island, he secured control of the southern sea and blocked the Japanese Navy from advancing to the West Sea. In the next sea battle at Busanjin, Yi's naval fleet was up against over 500 enemy warships and the battle raged into the next year. When it was over, all the Japanese warships were completely wiped out, which left the Japanese forces with no other option but to retreat under the pretext of a peace negotiation.
For all of Admiral Yi's heroic victories, the cunning plots of his treacherous subjects, the greed of Wongyun, and the wicked schemes of the Japanese worked together to strip Admiral Yi Sun-shin of his military position and forced him to serve as a commoner.
With Admiral Yi stripped of his post, the Japanese launched another massive invasion of Joseon Dynasty, which is referred to as the Japanese Invasion of 1597. With the Japanese Invasion of 1597 underway, Wongyun, who had succeeded Admiral Yi as Naval Commander-in-chief of the Three Provinces but was ignorant of naval strategies, lost every battle fought. The government then reinstated Admiral Yi as the Naval Commander of the Three Provinces. When Yi returned to Hansando Island, the situation was worse than imaginable. All the Admiral found was 12 war ships all but destroyed and 120 completely demoralized sailors. .King Seonjo ordered that with almost all the Joseon war ships annihilated, Yi should fight on land. Yi replied that he still had 12 war ships under his command and expressed his resolution to the king. Before Yi and his men engaged the Japanese war ships at Myeongnyang, he infused his soldiers with the courage for victory, then engaged the Japanese naval fleet of 133 war ships with his 12 ships and a handful of soldiers, destroying 31 of the Japanese war ships.
With victory at this naval battle as a turning point, the Joseon Naval Forces regained control of the seas. Not satisfied with this achievement, Admiral Yi relocated his naval camp to the Gogeumdo Islands and concentrated on building up his naval forces again.
Having been informed of about 500 Japanese war ships assembled in Noryang set to return to Japan on November 19, 1598, toward the end of the second Japanese Invasion, Yi persuaded the unwilling Ming Naval Commander to attack the Japanese fleet together.
Under Yi's brilliant leadership and superior tactics, the Japanese naval fleet lost most of their ships and soldiers in the battle. Unfortunately, during the course of the battle, Admiral Yi was hit by a stray bullet fired by a retreating enemy soldier and died. But before his death, Yi said, "Since the battle is at its peak, do not announce I am dead," further testimony to his strong sense of patriotism. Admiral Yi Sun-shin's tomb is located on Mount Eorasan in Eumbong-myeon, Asan-si, and a religious service is held to pay tribute to Admiral Yi at Hyeongchungsa Temple.