Taejo Wang Geon
Songak magnate who served Gung Ye, took Naju, overthrew Gung Ye to found Goryeo in 918 and reunified the Later Three Kingdoms in 935–936
In 903 he led a fleet to take Naju behind Later Baekje’s lines and married the daughter of the local magnate O Da-ryeon (Queen Janghwa). The year after founding Goryeo he moved the capital to Songak. He was badly defeated by Gyeon Hwon at Gongsan in 927 but seized the initiative by winning at Gochang in 930. In 935 he accepted the surrender of King Gyeongsun of Silla and made him sasimgwan of Gyeongju, and in 936 he defeated Singeom at Illicheon. He also took in Balhae refugees, including Crown Prince Dae Gwang-hyeon.
He won over the hojok by marrying their daughters and granting the royal surname Wang, and kept them in check with the sasimgwan and giin systems. He cut taxes to one-tenth of the harvest, set up the Heukchang granaries and granted merit land (yeokbunjeon) in 940. He made the Western Capital (Pyongyang) the base for northern expansion and spurned the Khitan in the Manbugyo incident of 942. He left the Ten Injunctions and the Jeonggye and Gyebaengnyoseo, guides for officials.