Yi Kuji was an illegitimate daughter of
Prince Yangnyeong, first son of the third Joseon king,
Taejong of Joseon and
Queen Wongyeong. Her mother was a palace slave of Crown Prince Yangnyŏng, whom he had two children with. She had an older sister. Yi was given the title of Princess () and married Kwŏn Tŏgyŏng (), a lesser official, and went to live in
Gwangju, her husband's hometown. They had two sons and one daughter. Kwŏn died in 1470 and Yi was prevented from remarrying by social stigma, then by the issuing of the Anti-Remarriage Law of 1477.
Investigation In 1475, it was reported to the
Saheonbu that Yi had been cohabiting with Ch'ŏllye, her slave. Hŏ Kye (), the head department of the Saheonbu, requested that the situation be investigated without resorting to interrogation. He proposed that Ch'ŏllye be moved to his residence, where the man could be questioned. One official reported that his son travelling from
Gwangju had heard rumours of an aristocratic lady who was liaising with a slave, while another official said that his servant had observed Ch'ŏllye sleeping and eating in the room next to his mistress' bedchamber.
Seongjong, however, refused to arrest Yi based on gossip alone. which some argued should apply only to common people and not the private affairs of an aristocratic lady. Ch'ŏllye died during the interrogation and more than 40 people were arrested. Though some members of the government argued that death was too strong a punishment for a woman of the royal clan, it was agreed that death was more respectful than torture, and Yi was condemned. Yi’s daughter, Jun-bi, was not involved in her mother’s investigation as she had already left home in 1488, a year before Yi was executed, and was considered a part of her husband’s family. == Posthumous ==