Duke of Joseon

King Yangheon (died 1099; born Wang Do) was a Goryeo Royal Prince as the first and oldest son of King Munjong and Consort Ingyeong who would become the grandfather of the future Queen Janggyeong, Queen Uijeong, and Queen Seonjeong. He was known as Marquess Joseon and Duke Joseon during his lifetime.

Early life and disputation of birth year
Born as the eldest son of Munjong of Goryeo and Princess Suryeong, he was named Do and have 2 younger brothers: Wang Su and Wang Yu. Although the year when he was born is unknown, but based on "Epitaph of Yi Ja-yeon", at the death of Yi in 1061, only three names that recorded as his royal grandsons: the crown prince, Marquess Gukwon, and Wang Do. From this, it was believed that Wang Do was born before Sukjong in 1054 or Uicheon in 1055.

Life and marriage
Wang Do's years of becoming the Marquess Joseon is unclear, but it was recorded in 1061 (based on Goryeosa) or in 1062 (based on Goryeosajeoryo). He was later honoured as Duke Joseon in 1077 (31st years reign of his father) and appointed as Sutaebo  in 1086. In 1094 (ascension year of King Heonjong), he became Sutaesa and Susado  a year later along with received 5000 sik-eup and 500 siksil-bong.

Wang Do was married with the second daughter of one of his maternal uncle, Yi Jeong and they had three sons together. Their second son would marry Princess Ansu who was one of King Sukjong's daughter while their third son's children were all marrying King Injong's children (Queen Janggyeong, Marchioness Daeryeong, Queen Uijeong, Queen Seonjeong, Wang Yeong).

In 1099 (4th years reign of King Sukjong), Duke Joseon died and received name Yangheon as his Posthumous name given by Sukjong own. According to the "Epitaph of Wang Won", the late Duke Joseon was later honoured as King Yangheon of Joseon State and following this, his wife, Lady Yi was honoured as "Queen Consort Yangheon".

Family

 * Father: Munjong of Goryeo (고려문종, 29 December 1019 – 2 September 1083)
 * Grandfather: Hyeonjong of Goryeo (고려현종, 1 August 992 – 17 June 1031)
 * Grandmother: Queen Wonhye of the Ansan Gim clan (원혜왕후김씨; d. 31 July 1022)
 * Mother: Worthy Consort Ingyeong of the Incheon Yi clan
 * Grandmother: Lady Gim, of the Gyeongju Gim
 * Grandfather: Yi Ja-yeon
 * Consorts and their Respective issue(s):
 * 1) Queen Yangheon, of the Inju Yi clan
 * 2) Wang Ja, first son
 * 3) Wang Won (광평공 왕원, 1083–1170), Duke Gwangpyeong, second son
 * 4) Wang On (강릉공 왕온, d.1146), Duke Gangreung, third son