King Sejong the Great (세종대왕 ; 世宗大王) (April 10, 1397-February 10, 1450), born Yi Do (이도 ; 李祹), was the fourth ruler of the Joseon Dynasty of Korea (at that time called Joseon) from 1418 to 1450. He was also a skilled linguist under whose guidance the native Korean alphabet Hangeul was created. In addition to Hangeul, Sejong also invented rain gauge, striking water clocks, and sundial. Following the principles of Neo-Confucianism, Sejong was also a humanitarian who proclaimed that there must be three trials before a final judgment is reached, and he prohibited brutality in the punishment of criminals, such as flogging.
Sejong was the third son of King Taejong (Yi Bangwon). When he was ten, he became Grand Prince Chungnyeong (충녕대군 ; 忠寧大君) and married Sim On (심온 ; 沈溫) of Cheongsong (청송 ; 青松), commonly known as Sim-ssi (침씨 ; 沈氏), who later was given the title Princess-Consort Soheon (소헌왕비 ; 昭憲王妃). Established the Hall of Worthies (집현전 ; 集賢殿 ; Jiphyeonjeon) in 1420 in the royal palace, Sejong gathered intellectuals from around Korea. The scholars of the Hall of Worthies documented history, drafted documents and compiled books on various topics.
In addition to being a linguist and an inventor, Sejong was also a writer. He composed Yongbi eocheon ga ("Songs of Flying Dragons", 1445), Seokbo sangjeol ("Episodes from the Life of Buddha", July 1447), Worin cheon-gang jigok ("Songs of the Moon Shining on a Thousand Rivers", July 1447), and the reference Dongguk jeong-un ("Dictionary of Proper Sino-Korean Pronunciation", September 1447).
Sejong died at the age of 52 and was buried at the Yeong Mausoleum (영릉 ; 英陵). His successor was his first son, Munjong.
List of Koreans.