Gukjo of Goryeo
Gukjo of Goryeo nominated Wang Yung as Sejo of Goryeo and Jakjaegeon as Uijo of Goryeo. For Gukjo, there are some stories. His posthumous name was the great Wondeog.Biography
According to Pyeonnyeon-Tong-Long and Goryeosa jeolyo, Gukjo was Gang Bo Yuk.
Gang Chung was a son of Gang Ho-gyeong who was the 67th descendant of Gang Hou. Gang Hou was the second child of Gang Shu who was from Zingzhao country, Shangxi province in China. He had three children named as I-Jegeon, Bo-Seung and Gang Bo Yuk. Gang Bo Yuk married with his niece Gang Deju and their daughter Gang Sin-ui was born. Gang Sin-ui married with Chinese man and King Uijo of Goryeo was born. The father of King Uijo was royal family from Tang dynasty, China. According to Pyeonnyeon-Tong-Long and Goryeosa jeolyo, he was Emperor Suzong of Tang. In Pyeonnyeongangmog, Emperor Xuānzong of Tang was father of King Uijo. When his father visited Silla, King Uijo of Goryeo was born between his Chinese father and Gang Sin-ui who was a daughter of Gang Bo Yuk. On the way of finding his father to China, King Uijo met Queen Wonchang and get married with her. According to Record of Seongwon, Queen Wonchang was a daughter of Tou En Dian Jiao Gan from Ping state, China. Queen Wonchang gave birth of a boy. His name was Wang Ryung and his son was the founder of Goryeo, Taejo of Goryeo.