Sejong (Korean: 세종; Hanja: 世宗; 10 April 1397 – 17 February 1450),[b][c] personal name Yi Do (이도; 李祹), commonly known as Sejong the Great (세종대왕; 世宗大王), was the fourth monarch of the Joseon dynasty of Korea. Today, he is regarded as one of the greatest rulers in Korean history, and is remembered as the inventor of Hangul, the native alphabet of the Korean language