Explore history of King Sejong and Admiral Yi Sun-shin Two statues stand at Gwanghwamun Square representing two iconic figures of Korean history: Adm. Yi Sun-shin, a national hero who triumphed over Japanese invaders during the Imjin War (1592-1598), and King Sejong, an ingenious ruler who invented Hangeul, the Korean writing system, in 1443. Two permanent exhibitions have been set up underneath these statues, housed in the basements of Gwanghwamun Square and the Sejong Center for the Performing