Isabu was a fourth-generation descendant of King Naemul of Shilla. In the 13th year of King Jijeung (A.D 512), he captured Usanguk (Ulleungdo and Dokdo areas presently)
as the governor of Haseullaju (Gangneung area presently). At that time, Usanguk was an independent tribal nation by the seas. Because of its people’s aggressiveness and fieriness,
it was not easy to defeat. Therefore, Isabu came up with a wise tactic. He made wooden lions, arranged them on his vessels, and proceeded to Usanguk. Then, he said, "if you don’t
surrender, I’ll release these hungry lions and have them eat you." As a result, the people of Usanguk surrendered obediently and promised to pay taxes to Shilla every year.
Later on, Isabu became Ichan (the second highest position in Shilla’s Cabinet) in the 2nd year of King Jinheung (A.D 541). He also advised the King about the importance of organizing a national history and appointed Geo, Chilbu to publish Shilla′s national history. Dokdo has been a territory of Korea since the time of Isabu.