Background
He was the second son of Hyeonjong, and the younger brother of Deokjong.
He was the second son of Hyeonjong, and the younger brother of Deokjong.
At the age of four in 1022, he was made Naesaryeong, a position of high rank, and designated the Prince of Pyongyang. Jeongjong II was greatly concerned with national defense, and began constructing fortresses along the northern border in the first year of his reign. In 1037, the country suffered an invasion from the northern Khitan tribes.
In 1044, the Cheolli Jangseong was completed, an enormous wall across northern of Korea.
Jeongjong II 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 II established primogeniture as national law.
