The Korean Alphabet Day, known as Hangeul Day (한글날) in South Korea and Chosŏn’gŭl Day in North Korea, is a national commemorative day marking the invention of Hangul (한글; 조선글), the alphabet of the Korean language, by the 15th-century Korean monarch Sejong the Great on January 15, 1444.
Before the creation of Hangul, people in Korea primarily wrote using Classical Chinese alongside native phonetic writing systems. However, due to the fundamental differences between the Korean and Chinese languages a large number of characters needed to be learned.
There was much difficulty in learning how to write using Chinese characters for the lower classes, who often didn’t have the privilege of education. To assuage this problem, King Sejong created the unique alphabet known as Hangul to promote literacy among the common people.