Korea's official script is Hangul, the unique Korean Alphabet. This name, a compound of han, meaning, "the Korean people" or "great" and gul, meaning "Letters" was given to it early in the 20th century.
The creator of Hangul was King Sejong the Great (reigned 1418~1450), fourth king of the Chosun Dynasty.
Sejong was concerned that Chinese characters, until that time used to write Korean, were a writing system for representing Chinese, a language completely different structually from Korea and were therefore hard for Koreans to learn and use. In the twelfth lunar month of 1443 he completed development of a writing system suitable for representing Korean, which he called Hunminjungum, "Proper sounds to instruct the people".

Hunminjungum was an alphabet formed of 28 letters. Today's Hangul uses only 24 of these, having dropped four. This orthography not only represents the Korean language perfently but also is easy to learn and use. It is recognized as being both original and scientific.

Seijong himself wrote a preface clarifying the origin and the purpose of the new alphbet and giving brief examples and explanations of each of its letters, while he had the scholars of the Jiphyongjon, or "Hall of Worthies" gice detailed explanations and examples of them.
The resulting work was published in the ninth lunar month of 1446, and the new alphabet was widely made known to the public. The work's title was the same as the then name of the alphabet, Hunminjungun. The recently discovered complete edition is known as the Haerye Edition of Hunminjungun (haerye regerring to the explanations and examples of the Jiphyonjon scholars, which were missing in the previously known edition)
Annals of Chosun Dynasty