What is "taewang"

Taewang, meaning "The Greatest of all Kings", was a title of imperial rank used by the rulers of Goguryeo, one of the Three Kingdoms of Korea, since the reign of Gwanggaeto the Great.

Although it does not signify emperor itself, the Taewang title granted the ruler of Goguryeo equal power and status with the Chinese emperor. Also some Silla rulers including Beopheung and Jinheung used this title for their declaration of independence from the influence of Goguryeo.