Sejong the Great (May 15, 1397 – April 8, 1450, r. 1418–1450) was the fourth king of Joseon-dynasty Korea. Born with family name Lee (; ), given name Do (; ), family origin Jeonju (; ), sobriquet Wonjeong (; ). Posthumous name is Sejong (; ). Posthumous title, abbreviated, is Jang Heon Great King (; ), and official title is Sejong Jangheon Yeongmun Yemu Inseong Myeonghyo Daewang (; ). He was the third son of King Taejong and Queen-Consort Min. He was designated as heir-apparent, Crown Prince, after his older brother Jae was stripped of his title. He ascended to the throne in 1418. During the first four years of his reign, Taejong governed as regent, after which his father-in-law, Sim On, and his close associates were executed.