Sejong the Great, Korean king (b. 1397)
Sejong the Great (세종대왕, Korean pronunciation: [se̞(ː)dzo̞ŋ dewaŋ]; 15 May 1397 – 8 April 1450) was the fourth ruler of the Joseon Dynasty of Korea. He was the third son of King Taejong and Queen Wongyeong, and was designated as Crown Prince after his older brother, Grand Prince Yangnyeong, was stripped of his title. He ascended to the throne in 1418, but during the first four years of his reign, Taejong governed as regent and executed Sejong's father-in-law, Shim On, and his close associates.

Sejong reinforced Korean Confucian and Neo-Confucian policies, and enacted major legal amendments (공법; 貢法). He personally created and promulgated the Korean alphabet Hangul, encouraged advancements of science and technology, and introduced measures to stimulate economic growth. He dispatched military campaigns to the north and instituted the Samin policy (사민정책; 徙民政策) to attract new settlers to the region. To the south, he helped subjugate Japanese pirates, during the Ōei Invasion. He is regarded as one of the greatest kings in the history of Korea.

After his father's death, he governed as the sole monarch from 1422 to 1450, although after 1439 he became increasingly ill, and starting from 1442, his son, Crown Prince Yi Hyang (the future King Munjong), acted as regent.