Born into a noble family, Yi rose to power through strategic marriages and political maneuvering, becoming a pivotal figure in the royal court.
Goryeosa, where it catalogs notable traitors throughout Goryeo history, dedicates a biography to Yi's service and corruption in the royal court.
The union was Yejong's effort to appease the court officials who protested his military campaign against the Jurchens, since Yi Cha-gyŏm's father-in-law, Ch'oe Sa-chu, wielded significance political influence in Goryeo and Yi's brother-in-law, Kim In-jon, was a prominent figure in Goryeo's court and vehemently against the war with the Jurchens.
One day, Yi Cha-gyŏm dispatched a private envoy to the Song dynasty, seeking appointment as the king's regent (지군국사; 知軍國事), without consulting Injong.
With Injong's consent, they intended to enlist support from military generals who harbored animosity toward Ch'ŏk Chun-gyŏng, a close ally and relative of Yi.
Yi became aware of the covert plot and gathered his allies to seek a resolution, but their efforts proved futile, knowing that any retaliatory action would constitute a coup d'etat.
However, Yi faced challenges in accepting Injong's decision due to public sentiment and societal norms, which viewed such actions as treason and usurpation.
[6] Scores of Injong's co-conspirators and soldiers were either executed or exiled,[6] and the tumultuous events of the preceding four days only strengthened Yi Cha-gyŏm's hand.
During the dispute, Yi Chi-ŏn's slave accused Ch'ŏk Chun-gyŏng of setting fire to the royal palace, suggesting he deserved execution.
[7] During that period, Yi Cha-gyŏm placed great trust in Korean traditional divination (파자점; 破字占), which involved the breakdown and analysis of Chinese characters to derive meaning or predictions.
Upon reading the letter and incensed by Yi Cha-gyŏm's brazen attempts to assassinate the king, Ch'ŏk finally aligned himself with Injong.
Upon realizing the shift in fortunes and understanding the situation was no longer in his favor, Yi Cha-gyŏm surrendered himself without resistance, and without wearing his official robe.
[10] During his exile in South Jeolla Province, Yi allegedly ate dried yellow corvina and coined the name "Yeonggwang Gulbi (영광 굴비; 靈光 屈非) ," combining the place of his exile, Yeonggwang, with "gulbi," which signifies determination or resilience, indicating his refusal to yield.
Despite the usual fate of exiles being forgotten, Injong maintained respect for Yi as his maternal grandfather and childhood guardian.