Usan-guk
Usan-guk ( Korean : 우산국 ) was a Korean state that consisted of Ulleung-do and the adjacent islands during the Three Kingdoms period . According to the Samguk Sagi , it was conquered in 512 by the Silla General Kim Isabu . He is said to have used wooden lions or tigers to get the residents to surrender. It is claimed that Usan-guk's middle name is Ulleung-do. Usan-guk then appeared rarely in historical records, but seems to have led a largely autonomous existence until its annexation by Goryeo in 930.
Usan-guk probably consisted of Ulleung-do and Jukdo or the Liancourt Rocks .