Goryeo
Silla had accomplished a unification of the Three Kingdoms of Korea in 668. But it weakened as local lords achieved power during the end of the 9th century. The country entered a period of civil war and rebellion, led by Gung Ye, Gi Hwon, Yang Gil, and Gyeon Hwon. Gung Ye established Hugogureo (meaning "Later Goguryeo") and Wang Geon (Later, Taejo) made a contribution as Gung Ye's subordinate. However, Gung Ye became more and more tyrannical and finally killed his own wife and son. Also he insisted that he was Maitreya (the future Buddha). Meanwhile, Wang Geon increased his power as he conquered Geumsung area in Later Baekje. Finally, some people who followed Wang Geon broke out the rebellion and he named the dynasty as Goryeo and changed its capital city to Song-ak.