It was introduced by [[King Sejong]] in the 15th century in an effort to increase literacy. Sejong boasted that a clever person could learn Hangul in a day, while a fool could learn it in a week. However, Hangul wasn't widely used until the early 20th century. | It was introduced by [[King Sejong]] in the 15th century in an effort to increase literacy. Sejong boasted that a clever person could learn Hangul in a day, while a fool could learn it in a week. However, Hangul wasn't widely used until the early 20th century. |