Sejong the Great (세종대왕, Korean pronunciation: [se̞(ː)dzo̞ŋ de̞waŋ]; Middle Korean: Syéoig jong ōéog jyéoig? 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.