Sejong, personal name Yi Do, commonly known as Sejong the Great, 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.

Korean is the native language for about 81 million people, mostly of Korean descent. It is the official and national language of both North Korea and South Korea. The language has notable differences in each of the Koreas, in part owing to different official standardizations of the language. They are still largely mutually intelligible, however. South Korean newspaper Daily NK has claimed North Korea criminalizes the use of the South's standard language with the death penalty, and South Korean education and media often portray the North's language as alien and uncomfortable.