Yi Sun-sin was born on April 28, 1545 in the aristocratic neighborhood of Geonchondong, Hansung (now Seoul) as the third son of Yi Chong and his wife Byun. Although he was of good ancestry, his family was not well off because his grandfather had been embroiled in a political purge during the reign of King Joong Jong and Yi’s father stayed away from seeking a civil service job. When the economic situation worsened for his family, they moved to Asan, the country home of Yi’s maternal family.

At the age of 21, he married a woman from a neighboring town and had three sons and a daughter. Like any other young man of aristocratic family, he studied Confucian classics from an early age. But he began to train in the military arts when he turned 22. Although Yi was fully aware that the literary tradition was more highly regarded than the military tradition in his society, he chose the military service because of his personal conviction. But the refined writings in his dairy, reports, and poems demonstrate that he had remarkable literary talent as well as the valor and brilliance of a warrior.

In 1572, when he was 28, Yi took a military service examination. During the exam, he fell from horseback and broke his left leg. The crowd was astonished when they saw him quietly get up on one leg to bind the broken leg with a branch from a nearby willow tree. Four years after his first trial, without giving up, he took the exam again and, at the age of 32, he passed the military service examination.

Thereafter, he was always true to his duties as a military officer while stationed at various locations. However, because of his unwillingness to compromise his integrity, he did not seek favors from those in power. As a result, Yi’s military career languished and his accomplishments went unnoticed. Once, he was even relieved of his post for refusing to participate in unlawful activities solicited by his superior. Also, he experienced a harsh demotion to a common foot soldier as result of false accusations by another officer who blamed Yi for his own mistake. Then, just a few months before the outbreak of war, he received an exceptional promotion and became the Commander of Cholla Left Naval Station thanks to the vigorous recommendation from Prime Minister Yu, who had known Yi since childhood and firmly believed that Choson Korea was in need of his abilities.

As soon as he became a naval commander, he took up the task of reviving and restoring the Korean Naval Force. He straightened the administrative system, improved the condition of weapons and tightened sailors’ discipline even though it was not yet clear that war was imminent. He also put his efforts in making warships and completed building a Turtle Ship just a day before the Japanese invasion. In the following seven years, Yi saved his homeland and his people by leading all his 23 naval engagements to victory with his unshakable loyalty, brilliant tactics, and indomitable spirit that transcended life and death.

While he accomplished unbelievable feats at sea as an Admiral, Yi suffered continuous tragedies and hardships in his personal life, which makes his life even more remarkable. Even when he was faced with a King who tried to kill him, his loyalty to his country never wavered. He did not harbor a grudge against Won Kyun and his enemies at king’s court for falsely accusing him of treason. When the Korean Navy he had built with so much care was from Won Kyun's disatrous defeat against the Japanese Navy, he did not allow his anger and resentment to stop him from carrying out his duties. His absolute loyalty to his country and people enabled him to achieve a maritime miracle of uninterrupted victories. In 1598, at the age of 54, he died gloriously in his final battle at Noryang, which concluded the Seven Year War. He was posthumously titled Chung Mu Gong (Duke of Loyalty and Art of Chivalry).