Who they were
Joseon’s great admiral in the Imjin War, by traditional count undefeated in some twenty-three naval engagements. His fleet included the armored “turtle ships” (geobukseon), though details of their construction are debated.
What they did
His fleet severed Japanese supply lines; the victory at Hansando (1592) was the war’s naval turning point. Dismissed and tortured through court intrigue, he was reinstated after the fleet he left behind was destroyed at Chilcheollyang (1597). At Myeongnyang (1597) he prevailed with thirteen ships against a fleet traditionally counted at well over a hundred. He was killed by a stray shot at Noryang (December 1598), the war’s last battle — tradition says he ordered his death concealed until victory.
Legacy
His war diary, Nanjung Ilgi, is UNESCO Memory of the World. Korea’s supreme national hero — his statue commands Gwanghwamun square in Seoul — and a naval commander studied worldwide.