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Jeongjong of Goryeo (31 August 1018 – 24 June 1046), personal name Wang Hyŏng, was the 10th king of Korea's Goryeo dynasty. He was the second son of King Hyeonjong, and the younger brother of King Deokjong. At the age of four in 1022, he was made Naesaryeong, a position of high rank, and designated the Prince of Pyongyang.

Jeongjong was greatly concerned with national defense, and began constructing fortresses along the northern border in the first year of his reign. In 1037, Goryeo was invaded by the Liao dynasty.^{[citation needed]} In 1044, the Cheolli Jangseong was completed, an enormous wall across northern Korea.^[1][2] Jeongjong also concerned himself with the material support of the army, distributing state land to indigent soldiers in 1036.

Just before his death in 1046, Jeongjong established primogeniture as national law.^{[citation needed]}

• Father: Hyeonjong of Goryeo
  • Grandfather: Anjong of Goryeo
  • Grandmother: Queen Heonjeong
• Mother: Queen Wonseong
  • Grandfather: Kim Ŭn-bu
  • Grandmother: Grand Lady of Ansan County of the Gyeongwon Yi clan (안산군대부인 이씨)
• Consorts and their Respective Issue(s):

1. Queen Yongsin of the Danju Han clan
   1. Wang Hyŏng
2. Queen Yongui of the Danju Han clan
   1. Wang Bang, Prince Aesang
   2. Wang Gyeong, Marquess Nakrang
   3. Wang Gye, Marquess Gaeseong
3. Queen Yongmok of the Buyeo Yi clan
   1. Princess Doae
4. Virtuous Consort Yongjeol of the Gyeongju Kim clan – No issue.
5. Princess Yeonchang of the No clan – No issue.

• List of Korean monarchs
• List of Goryeo people
• Jeongjong, 3rd Monarch of Goryeo

• 정종 (in Korean). Doosan Encyclopedia.