He was born in 1450 as the second son of Grand Prince Suyang (as
King Sejo was known at the time) and his primary consort, Grand Internal Princess Consort Nakrang (later
Queen Jeonghui). He was promoted to crown prince at the age of 7, after the sudden death of his elder brother,
Crown Prince Uigyeong. In 1468, his father abdicated, but since Yi Hwang was not yet 20 years old and had been physically weak since his childhood, his mother,
Queen Dowager Jaseong, came to unofficially rule as Queen Regent for the nation instead. According to records of this era, political decisions were taken by the queen and three subjects nominated by King Sejo. Although his reign lasted just 14 months, several incidents had occurred. In 1468, the treason of Nam I greatly influenced the court politics. Just before his death in 1469, Joseon started to prohibit all trade with Japan. Yi Hwang also granted common farmers the right to cultivate fields which originally belonged to the military. He died shortly before his 20th birthday and was buried alongside his second wife,
Queen Ansun, in the Seooneung Cluster located in
Goyang,
Gyeonggi Province. Their tomb is known as
Changneung (). After Yejong's death, the throne was not inherited by his son. Instead, his nephew and the second son of Crown Prince Uigyeong, Grand Prince Jalsan, became the heir and was posthumously honored as
King Seongjong. Both of Yejong's sons, Grand Prince Inseong and Grand Prince Jean, died without issue. In 1874, during the reign of
Gojong, Yi Ong, Prince Seoseong of the Third Junior Rank (; 1487–1510) and a great-great-grandson of
Sejong the Great, was posthumously appointed as heir to Grand Prince Inseong. Similarly, (; 1515–1571), a great-great-grandson of
Jeongjong of Joseon, was also granted the title Prince Nakpung (
Nakpung Gun; 낙풍군) and became heir to Grand Prince Jean. ==Family==